Hybrid battery control system architecture systems and methods

ABSTRACT

One embodiment of the present disclosure describes a battery system that includes a battery string with a first and second battery module; and a battery control system. The battery control system includes a first cell control that determines first module level operational parameters related to operation of the first battery module; a second cell control that determines second module level operational parameters related to operation of the second battery module; a string control unit communicatively that determines string level operational parameters related to operation of the battery string based at least in part on the first and second module level operational parameters; and a system control unit that determines system level operational parameters related to operation of the battery system based at least in part on the string level operational parameters; and controls operation of the battery system based at least in part on the system level operational parameters.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from and the benefit of U.S.Provisional Application Ser. No. 62/250,989, entitled “FLEXIBLE SCALABLEBATTERY MANAGEMENT SYSTEM,” filed on Nov. 4, 2015, which is incorporatedby reference in its entirety for all purposes.

BACKGROUND

The present disclosure generally relates to battery systems and, morespecifically, to battery control systems utilized in battery systems.

This section is intended to introduce the reader to various aspects ofart that may be related to various aspects of the present disclosure,which are described below. This discussion is believed to be helpful inproviding the reader with background information to facilitate a betterunderstanding of the various aspects of the present disclosure.Accordingly, it should be understood that these statements are to beread in this light, and not as admissions of prior art.

Electrical systems often include a battery system to capture (e.g.,store) generated electrical energy and/or to supply electrical power. Infact, battery systems may be included in electrical systems utilized forvarious applications and/or with varying configurations. For example, astationary power system may include a battery system that receiveselectrical power output by an electrical generator and stores theelectrical power as electrical energy. In this manner, the batterysystem may supply electrical power to electrical loads using the storedelectrical energy.

Additionally, an electrical system in an automotive vehicle may includea battery system that supplies electrical power, for example, to provideand/or supplement the motive force (e.g., power) of the automotivevehicle. For the purpose of the present disclosure, such automotivevehicles are referred to as xEV and may include any one, any variation,and/or any combination of the following type of automotive vehicles. Forexample, electric vehicles (EVs) may utilize a battery-powered electricpropulsion system (e.g., one or more motors) as the primary source ofvehicular motive force. As such, a battery system in an electric vehiclemay be implemented to supply electrical power to the battery-poweredelectric propulsion system. Additionally, hybrid electric vehicles(HEVs) may utilize a combination of a battery-powered electricpropulsion system and an internal combustion engine propulsion system toproduce vehicular motive force. As such, a battery system may beimplemented to facilitate directly providing at least a portion of thevehicular motive force by supplying electrical power to thebattery-powered electric propulsion system.

Furthermore, micro-hybrid electric vehicles (mHEVs) may use an internalcombustion engine propulsion system as the primary source of vehicularmotive force, but may utilize the battery system to implement“Stop-Start” techniques. In particular, a mHEV may disable the internalcombustion engine when idling and crank (e.g., restart) the internalcombustion engine when propulsion is desired. To facilitate implementingsuch techniques, the battery system may continue supplying electricalpower while the internal combustion engine is disabled and supplyelectrical power to crank the internal combustion engine. In thismanner, the battery may system may indirectly supplement providing thevehicular motive force.

In any case, a battery system may include a battery control system thatcontrols (e.g., monitors and/or manages) operation of the batterysystem. For example, the battery control system may determineoperational parameters (e.g., voltage and/or current) of the batterysystem and instruct the battery system to adjust operation based atleast in part on the operational parameters. Thus, implementation of thebattery control system may vary based at least in part on implementation(e.g., configuration and/or organization) of the battery system.However, in some instances, implementation of the battery system mayvary based at least in part on target application and/or configurationof the electrical system utilizing the battery system.

SUMMARY

Certain embodiments commensurate in scope with the present disclosureare summarized below. These embodiments are not intended to limit thescope of the disclosure, but rather only to provide a brief summary ofcertain disclosed embodiments. Indeed, the present disclosure mayencompass a variety of forms that may be similar to or different fromthe embodiments set forth below.

The present disclosure generally relates to battery systems, forexample, used in an electrical system to capture (e.g., store)electrical energy and/or to supply electrical power using storedelectrical energy. In some embodiments, a battery system may includebattery control system used to control operation of the battery system.To facilitate controlling operation, a battery control system mayperform various functions, such as determining an operational parameterrelated to operation of the battery system and/or determining a controlcommand instructing the battery system to perform a control action.

In some embodiments, functions to be performed by a battery controlsystem may be dependent on implementation (e.g., hierarchalorganization) of the battery system. However, in some instances,implementation of battery systems utilized in different electricalsystem and/or different target applications may vary. As such, thefunctions performed by and, thus, implementation of different batterycontrol system may vary.

To facilitate improving implementation flexibility, the presentdisclosure provides techniques for determining a hybrid battery controlsystem architecture, which may be utilized to implement multipledifferent battery control system with reduced implementation associatedcost. In some embodiments, the hybrid battery control system may includebasic (e.g., standard) building blocks that may be used to implement abattery control system. For example, the hybrid battery control systemarchitecture may specify a cell control unit, a string control unit, anda system control unit as well as functions provided by each andinfrastructure in each to provide the corresponding functions.

Thus, in some embodiments, a design system may determine the hybridbattery control system architecture based at least in part on targetcontrol levels (e.g., granularity) and/or target functions to beprovided by battery control systems intended to be compatible (e.g.,implementable) using the building blocks provided in the hybrid batterycontrol system architecture. To facilitate determining the targetcontrol levels and/or the target functions, in some embodiments, thedesign system may analyze battery systems corresponding with the batterycontrol systems. In this manner, the design system may determineimplementation (e.g., hierarchal organization) of the battery systems.

For example, when a battery system includes a battery module withmultiple battery cells, the design system may determine that the targetcontrol levels include a cell control level and/or a module controllevel. Additionally, the design system may determine that the targetfunctions include module level functions, such as determining voltage ofthe battery module, and/or cell level functions, such as determiningvoltage of one or more battery cells. Furthermore, when a battery systemincludes a battery string with multiple battery modules connected inseries, the design system may determine that the target control levelsinclude a string control level and the target functions include stringlevel functions, such as determining operational parameters (e.g.,voltage or current) of the battery string and/or coordinating operationof the battery modules. Moreover, when a battery system includesmultiple battery strings, the design system may determine that thetarget control levels include a system control level and the targetfunctions include system level functions, such as coordinating operationof the battery strings.

In some instances, a battery control system may be implementable usingany one of multiple different battery control system architectures.However, each of the different battery control system architectures mayvarying effect on implementation flexibility and/or implementationassociated cost. Thus, in some embodiments, the design may select thehybrid battery control system architecture from multiple candidates, forexample, using an objective function that provides a metric for eachcandidate indicative of expected implementation flexibility and/orexpected implementation associated cost.

In some embodiments, to determine implementation flexibility, the designsystem may determine a number of different battery control systemsand/or number of target functions of the different battery controlsystems a candidate battery control system architecture is capable ofimplementing. Additionally, to facilitate determining implementationassociated cost, the design system may determine infrastructure used ina candidate battery control system architecture. In some embodiments,implementation associated cost may be reduced by reducing the number ofmicroprocessors, number of isolation barriers, and/or communicationinfrastructure used to implement a battery control system.

To facilitate improving implementation flexibility and/or reducingimplementation associated cost, in some embodiments, the hybrid batterycontrol system architecture determined by the design system may groupfunctions in the building blocks based at least in part on voltagedomain and/or control level hierarchy. Additionally, in someembodiments, the hybrid battery control system architecture maydistribute less computationally intensive functions, for example, in thecell control units to facilitate improving implementation flexibility.On the other hand, in some embodiments, the hybrid battery controlsystem architecture may centralize more computationally intensiveprocessing functions, for example, in string control units to facilitatereducing number of microprocessors and, thus, implementation associatedcost. Furthermore, in some embodiments, the hybrid battery controlsystem architecture may centralize communication between componentsoperating in different voltage domains (e.g., ranges), for example, instring control units to facilitate reducing number of isolation barriersand, thus, implementation associated cost.

Additionally, in some embodiments, the hybrid battery control systemarchitecture may include an integrated string control unit thatintegrates functionality of a cell control unit and a string controlunit. In other words, instead of a separate string control unit and cellcontrol unit, the battery system may be implemented with an integratedstring control unit. In this manner, implementing a battery controlsystem using the integrated string control unit, which may facilitatereducing communication infrastructure and, thus, implementationassociated cost.

Additionally, in some embodiments, the hybrid battery control systemarchitecture may enable string control units (e.g., integrated stringcontrol units) to be communicatively coupled via a serial communicationnetwork, for example, using one or more serial communication busses,such as a ripcord bus. In some embodiments, the serial communicationnetwork may communicatively couple the string control units in a daisychain, for example, with a master string control unit and one or moresubordinate control units. Utilizing the serial communication network,the string control units may communicate serial communication signalsthat facilitate self-configuration and/or fault indication.

For example, a master string control unit may generate a serialcommunication signal with a master frequency (e.g., 100 Hz), whichindicates that it is the master string control unit. Additionally, themaster string control unit may generate the serial communication signalwith a fault frequency to indicate that a fault has been detected. Themaster string control unit may then communicate the serial communicationsignal to a subordinate string control unit via a serial communicationbus.

Thus, based at least in part on the frequency of the serialcommunication signal, a subordinate string control unit may determinewhether a fault has been detected in the battery system. When a faulthas been detected, the subordinate string control unit may output aserial communication signal with the fault frequency to indicate that afault has been detected. On the other hand, when a fault has not beendetected, the subordinate string control unit may determine its order inthe serial communication network based at least in part on the receivedfrequency. For example, a string control unit may determine that it isthe first subordinate string control unit in the serial communicationnetwork when the received frequency is equal to the master frequency.

Additionally, a subordinate string control unit may determine an orderfrequency that indicates its order in the serial communication network.In some embodiments, the order frequency may be fraction of the receivedfrequency. For example, the order frequency (e.g., 50 Hz) determined bythe first subordinate string control unit in the serial communicationnetwork may be half the received frequency and, thus, half the masterfrequency (e.g., 100 Hz). The first subordinate string control unit maythen communicate the serial communication signal with the orderfrequency to a next subordinate string control unit in the serialcommunication network. In this manner, the next subordinate stringcontrol unit may determine that its order in the serial communicationnetwork is the second subordinate string control unit.

To facilitate detecting faults, in some embodiments, the hybrid batterycontrol system architecture may provide a cell control unit faultdetection capabilities. However, in some embodiments, the hybrid batterycontrol system architecture may include limited processing capabilitiesin the cell control unit to facilitate reducing implementationassociated cost. For example, instead of a microprocessor, the cellcontrol unit may include a first analog-to-digital (ADC) converter, asecond analog-to-digital converter, and logic circuitry, which performslogic operations and/or arithmetic operations based on circuitconnections formed in the logic circuitry.

Thus, to improve reliability of the battery system, the cell controlunit may be implemented to provide fault detection even with limitedprocessing capabilities. For example, in some embodiments, the firstanalog-to-digital converter may receive sensor data (e.g., analogrepresentation) from a voltage sensor and generate a first cell groupvoltage (e.g., digital representation) that indicates voltage measuredacross a first cell group in a battery module. Additionally, the secondanalog-to-digital converter may receive sensor data from a voltagesensor and generate a second cell group voltage that indicates voltagemeasured across a second cell group in the battery module. Furthermore,the second analog-to-digital converter may receive sensor data from avoltage sensor and generate a measured cell group voltage (e.g., digitalrepresentation) that indicate voltage measured across the batterymodule.

Based at least in part on the first cell group voltage and the secondcell group voltage, the logic circuitry may determine a calculatedbattery module voltage, for example, by summing the first cell groupvoltage and the second cell group voltage. Additionally, to determinewhether a fault is expected to be present, the logic circuitry maycompare the calculated battery module voltage with the measured batterymodule voltage. For example, in some embodiments, the logic circuitrymay determine that that a fault is expected to be present when a voltagedifference between the calculated battery module voltage and themeasured battery module voltage is greater than a difference threshold.In this manner, a hybrid battery control system architecture thatimproves implementation flexibility and/or reduces implementationassociated cost may be determined and used to implement various batterycontrol systems.

DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is block diagram of an electrical system including a batterysystem, in accordance with an embodiment of the present disclosure;

FIG. 2 is a perspective view of an automotive vehicle with theelectrical system battery system of claim 1, in accordance with anembodiment of the present disclosure;

FIG. 3 is a schematic diagram of the automotive vehicle of FIG. 2, inaccordance with an embodiment of the present disclosure;

FIG. 4 is a block diagram of the battery system of FIG. 1 including abattery control system, in accordance with an embodiment of the presentdisclosure;

FIG. 5 is a block diagram of a design system used to determine a targetarchitecture of the battery control system of FIG. 4, in accordance withan embodiment of the present disclosure;

FIG. 6 is a flow diagram of a process for operating the design system ofFIG. 6, in accordance with an embodiment of the present disclosure;

FIG. 7 is a flow diagram of a process for determining target functionsof the battery control system of FIG. 4, in accordance with anembodiment of the present disclosure;

FIG. 8 is a flow diagram of a process for determining infrastructure inthe battery control system of FIG. 4 used to implement the targetfunctions, in accordance with an embodiment of the present disclosure;

FIG. 9 is a block diagram of the battery system of FIG. 4 with thebattery control system implemented using cell control units, stringcontrol units, and a system control unit based on an examplearchitecture, in accordance with an embodiment of the presentdisclosure;

FIG. 10 is a block diagram of the system control unit of FIG. 9, inaccordance with an embodiment of the present disclosure;

FIG. 11 is a block diagram of a string control unit of FIG. 9, inaccordance with an embodiment of the present disclosure;

FIG. 12 is a block diagram of a cell control unit of FIG. 9, inaccordance with an embodiment of the present disclosure;

FIG. 13 is a block diagram of the battery system of FIG. 4 with thebattery control system implemented using the cell control units,integrated string control units, and the system control unit based onanother example architecture, in accordance with an embodiment of thepresent disclosure;

FIG. 14 is a block diagram of an integrated string control unit of FIG.13, in accordance with an embodiment of the present disclosure;

FIG. 15 is a flow diagram of a process for implementing the integratedstring control unit of FIG. 14, in accordance with an embodiment of thepresent disclosure;

FIG. 16 is a block diagram of a master string control unit andsubordinate string control units communicatively coupled via a serialcommunication bus daisy chain, in accordance with an embodiment of thepresent disclosure;

FIG. 17 is a flow diagram of a process for communicating a serialcommunication signal in the serial communication bus daisy chain of FIG.16, in accordance with an embodiment of the present disclosure;

FIG. 18 is a flow diagram of a process for operating a subordinatestring control unit based at least in part on the serial communicationsignal, in accordance with an embodiment of the present disclosure;

FIG. 19 is a plot of example serial communication signals output bystring control units in the serial communication bus daisy chain of FIG.16, in accordance with an embodiment of the present disclosure;

FIG. 20 is a block diagram of one battery module and one cell controlunit in the battery system, in accordance with an embodiment of thepresent disclosure; and

FIG. 21 is a flow diagram of a process for operating the cell controlunit of FIG. 20 to detect faults, in accordance with an embodiment.

DETAILED DESCRIPTION

One or more specific embodiments of the present disclosure will bedescribed below. In an effort to provide a concise description of theseembodiments, not all features of an actual implementation are describedin the specification. It should be appreciated that in the developmentof any such actual implementation, as in any engineering or designproject, numerous implementation-specific decisions must be made toachieve the developers' specific goals, such as compliance withsystem-related and business-related constraints, which may vary from oneimplementation to another. Moreover, it should be appreciated that sucha development effort might be complex and time consuming, but wouldnevertheless be a routine undertaking of design, fabrication, andmanufacture for those of ordinary skill having the benefit of thepresent disclosure.

Generally, a battery systems may be implemented to capture (e.g., store)electrical energy generated by one or more electrical generators and/orto supply electrical power to one or more electrical loads using storedelectrical energy. Leveraging these benefits, one or more battery systemare often included in an electrical system. In fact, battery system maybe utilized in electrical systems with varying configurations toimplement a wide-variety of target applications, for example, rangingfrom a stationary power system to a vehicular electrical system.

To facilitate implementing different target applications, theconfiguration of an electrical system and, thus, the battery system usedin the electrical system may be adjusted. For example, in one targetapplication, the electrical system may include a first electrical load(e.g., component) designed to operate using electrical power in a high(e.g., 48V, 600V, or 720V) voltage domain and a second electrical loadthat operates using electrical power in a low (e.g., 3V, 5V, or 12V)voltage domain. As such, the battery system may be implemented to supplyelectrical power to the first electrical load in the high voltagedomain.

In some embodiments, to facilitate providing the high voltage domain,the battery system may be implemented with multiple battery modules(e.g., packs) connected in series as one or more battery strings.Additionally, to facilitate provide providing sufficient electricalpower to operate the first electrical load, in some embodiments, thebattery system may be implemented with multiple battery modules and/ormultiple battery strings connected in parallel. Furthermore, the batterysystem and/or an external power source may be implemented to supplyelectrical power to the second electrical load in the low voltagedomain.

To control operation (e.g., storage of electrical energy and/or supplyof electrical power), a battery system may include a battery controlsystem. In particular, the battery control system may control operationof the battery system by performing various functions, such asdetermining operational parameters (e.g., voltage, current, and/ortemperature) related to operation of the battery system, communicatingthe operational parameters within the battery control system,communicating the operational parameters to an external communicationnetwork, and/or determining control commands instructing the batterysystem to perform control actions. For example, the battery controlsystem may determine operational parameters of one or more battery cellsin a battery module, one or more battery modules, one or more batterystrings, and/or the battery system as a whole. Additionally, the batterycontrol system may communicate the operational parameters to asupervisory control system that coordinates operation of sub-systems inthe electrical system. Furthermore, the battery control system maycommunicate a control command instructing a relay (e.g., circuitbreaker) to open when a fault is detected.

In some instances, the functions to be provided by a battery controlsystem may be dependent on implementation (e.g., hierarchalorganization) of the corresponding battery system. However, as describedabove, implementation of the battery system may vary when utilized indifferent electrical system and/or in different target applications. Inother words, battery control system used in different battery systemsmay vary in implementation, such as in provided functions and/or controllevels (e.g., granularity).

In some embodiments, a battery control system may be implemented using abattery control system architecture. For example, a purely centralizedbattery control system architecture may be designed for a specificbattery control system and, thus, limit implementation flexibility(e.g., number of compatible battery system variations). On the otherextreme, a purely distributed battery control system architecture mayincrease amount of redundant infrastructure to improve implementationflexibility, but result in increased implementation associated cost.

Accordingly, the present disclosure provides techniques for determininga hybrid battery control system architecture, for example, that improvesimplementation flexibility and/or reduce implementation associated cost.In some embodiments, the hybrid battery control system may include basic(e.g., standard) building blocks that may be used to implement a batterycontrol system. For example, the hybrid battery control systemarchitecture may provide a cell control unit with specificinfrastructure to provide specific cell level functions and/or modulelevel functions. Additionally, the hybrid battery control systemarchitecture may provide a string control unit with specificinfrastructure to provide specific string level functions. Furthermore,the hybrid battery control system architecture may provide a systemcontrol unit with specific infrastructure to provide specific systemlevel functions.

In some embodiments, a design system may determine the hybrid batterycontrol system architecture based at least in part on target controllevels (e.g., granularity) and/or target functions to be provided bybattery control systems intended to be implementable using the buildingblocks provided in the hybrid battery control system architecture.Additionally, in some embodiments, the design system may determine thehybrid battery control system architecture based at least in part oninfrastructure (e.g., processing, power, and/or communicationinfrastructure) expected to be used to implement the target functions.

To facilitate determining the hybrid battery control systemarchitecture, in some embodiments, the design system may analyzemultiple candidates using an objective function. In some embodiments,the objective function may provide a metric associated with a candidateindicative of expected implementation flexibility and/or expectedimplementation associated cost. For example, in some embodiments, theobjection function may target reducing number of processors, reducingnumber of isolation barriers, and/or reducing communicationinfrastructure. In this manner, the design system may select the hybridbattery control system architecture from the multiple candidates.

In some embodiments, the hybrid battery control system architecture maygroup functions in the various building blocks based at least in part onvoltage domain and/or control level hierarchy. For example, the hybridbattery control system architecture may group measurement functionsrelated to a battery module and/or battery cells in the battery modulein a cell control unit. Additionally, in some embodiments, the hybridbattery control system architecture may centralize external (e.g., fromthe battery control system) communication functions in a system controlunit, thereby reducing communication infrastructure utilized toimplement the external communication functions.

Furthermore, in some embodiments, the hybrid battery control systemarchitecture may centralize more computationally intensive processingfunctions in one building block. For example, the hybrid battery controlsystem architecture may centralize more computationally intensiveprocessing functions in a string control unit, thereby reducingprocessing infrastructure utilized to implement the processingfunctions. On the other hand, the hybrid battery control systemarchitecture may distribute less computationally intensive functionsbetween multiple different building blocks. For example, the hybridbattery control system architecture may distribute less computationallyintensive processing functions between a cell control unit, a stringcontrol unit, and a system control unit, thereby improvingimplementation flexibility by providing multiple different controllevels (e.g., granularity).

Additionally, in some embodiments, the hybrid battery control systemarchitecture may centralize (e.g., within the battery control system)communication functions between components operating in differentvoltage domains in one building block. For example, the hybrid batterycontrol system architecture may centralize communication betweenelectrical components operating in different voltage domains in a stringcontrol unit. In this manner, other building blocks may be implementedwithout isolation barriers, thereby reducing power infrastructure usedto implement communication functions.

As described above, a battery string may include one or more batterymodules connected in series. In other words, a battery string generallyincludes at least one battery module. Thus, in some embodiments, thehybrid battery control system architecture may include an integratedstring control unit that integrates functionality of a cell control unitand a string control unit. In other words, instead of a separate stringcontrol unit and cell control unit, the battery system may include asingle integrated string control unit. In this manner, the hybridbattery control system architecture may facilitate reducingcommunication infrastructure—particularly in less complex battery system(e.g., single battery module battery strings). In fact, in someembodiments, using an integrated string control unit may obviate using asystem control unit, for example, in battery systems with a singlebattery module and/or a single battery string.

In some embodiments, string control units (e.g., integrated stringcontrol units) may be communicatively coupled by a parallel (e.g.,primary) communication network, such as a Controller Area Network (CAN).To improve reliability of a battery control system, the string controlunits may also be communicatively via a serial (e.g., backup)communication network via one or more serial communication busses, suchas a ripcord bus. In some embodiments, the serial communication networkmay communicatively couple the string control units in a daisy chain,for example, with a master (e.g., first) string control unit and one ormore subordinate (e.g., second) control units.

Additionally, in some embodiments, the serial communication network mayenable the string control units to communicate serial communicationsignals used to facilitate self-configuration and/or fault indication.In some embodiments, a string control unit may generate a serialcommunication signal with a frequency that indicates its order in theserial communication network and/or whether a fault has been detected inthe battery system. For example, when a fault has not been detected, afirst string control unit may generate a serial communication signalwith a master frequency, which indicates that it is the master stringcontrol unit. On the other hand, when a fault has been detected, thefirst string control unit may generate the serial communication signalwith a fault frequency, which indicates that a fault has been detectedin the battery system.

By outputting the serial communication signal to a serial communicationbus, a string control unit may enable a subsequent string control unitin the serial communication network to determine that the fault has beendetected. For example, when a second string control unit receives aserial communication signal with the fault frequency from the firststring control unit, the second string control unit may confirm that afault has been detected and output a serial communication signal withthe fault frequency after the fault has been confirmed to indicate thata fault has been detected in the battery system.

Additionally, by outputting the serial communication signal to a serialcommunication bus, a string control unit may enable a subordinate stringcontrol unit to determine its order in the serial communication network.For example, when the second string control unit receives a serialcommunication signal with the master frequency from the first stringcontrol unit, the second string control unit may determine that thefirst string control unit is the master string control unit and, thus,it is the first subordinate string control unit in the serialcommunication network.

The subordinate string control unit may also determine an orderfrequency that indicates its order in the serial communication network.In some embodiments, the order frequency may be fraction of the receivedfrequency. For example, the order frequency determined by the secondstring control unit may be half the received frequency and, thus, halfthe master frequency. Thus, by communicating a serial communicationsignal with its order frequency to a third string control unit in theserial communication network, the string control unit may enable thethird string control unit to determine that it is the second subordinatestring control unit in the serial communication network.

As described above, a string control unit may determine whether a faultis expected to have occurred in the string control unit, cell controlunits communicatively coupled to the cell control unit, and/or batterymodules electrically coupled to the cell control units. Additionally, asdescribed above, the hybrid battery control system architecture maycentralize computationally intensive functions in a string control unit.Thus, in some embodiments, a string control unit may include a processor(e.g., a processor unit and/or processing circuitry), which may enablethe string control unit to execute more complex data analysis operationsto detect faults.

On the other hand, in some embodiments, the hybrid battery controlsystem architecture may provide a cell control unit with limitedprocessing capabilities to facilitate reducing implementation associatedcost. However, this may limit complexity of data analysis operations thecell control unit is capable of executing. For example, instead of aprocessor, a cell control may include a first analog-to-digital (ADC)converter, which determines an indication of operational parameters(e.g., voltage) of a first battery cell group in a battery module, asecond analog-to-digital converter, which determines an indicationrepresentation of operation of operational parameters of a secondbattery cell group in the battery module and of the battery modules as awhole, and logic circuitry.

In some embodiments, the logic circuitry may perform logic operationsand/or arithmetic operations based on circuit connections formed in thelogic circuitry. For example, the logic circuitry may include arithmeticcircuitry, such as one or more logic gates. Additionally, the logiccircuitry may include comparison circuitry, such as one or moreoperational amplifiers. Thus, in some embodiments, the processingcapabilities of the logic circuitry may be more limited compared to aprocessor.

Nevertheless, the hybrid battery control system architecture may enablethe cell control units to be implemented with fault detectioncapabilities. For example, the first analog-to-digital converter maydetermine an indication (e.g., digital representation) of the firstbattery cell group voltage. Additionally, the second analog-to-digitalconverter may determine an indication of the second battery cell groupvoltage as well as a first indication of the battery module voltage.Based at least in part on the first battery cell group voltage and thesecond battery cell group voltage, the logic circuitry may determine asecond indication of the battery module voltage. Additionally, the logiccircuitry may compare the first indication of the battery module voltagewith the second indication of the battery module voltage to determinewhether a fault is expected to be present in the cell control unit. Forexample, the logic circuitry may determine that a fault is expected tobe present when the two vary by more than a threshold (e.g., voltage orpercentage). In this manner, a hybrid battery control systemarchitecture that improves implementation flexibility and/or reducesimplementation associated cost may be determined and used to implementvarious battery control systems.

To help illustrate, an electrical system 10 including a battery system12 is shown in FIG. 1. In addition to the battery system 12, theelectrical system 10 also includes an electrical source 14, anelectrical load 16, and a supervisory control system 18. In someembodiments, the supervisory control system 18 may control operation ofthe electrical system 10. For example, the supervisory control system 18may determine operational parameters of and/or coordinate operation ofsub-systems (e.g., the battery system 12, the electrical source 14,and/or the electrical load 16) in the electrical system 10.

To facilitate controlling operation, the supervisory control system 18may include a supervisory processor 20 and supervisory memory 22. Insome embodiments, the supervisory memory 22 may include a tangible,non-transitory, computer readable medium that stores instructionsexecutable by the supervisory processor 20. Thus, in such embodiments,the supervisory memory 22 may include random access memory (RAM), readonly memory (ROM), rewritable non-volatile memory (e.g., flash memory),hard drives, optical discs, and the like. Additionally, the supervisoryprocessor 20 may include one or more general purpose processing unitsand/or processing circuitry. For example, the supervisory processor 20may include one or more microprocessors, one or moreapplication-specific integrated circuits (ASICs), and/or one or morefield programmable logic arrays (FPGAs).

As described above, the battery system 12 may store received electricalpower as electrical energy and supply electrical power using the storedelectrical energy. Thus, as depicted the battery system 12 iselectrically connected to the electrical source 14, which may enable theelectrical source 14 to supply electrical power to the battery system12. In some embodiments, the electrical source 14 may include one ormore machines, components, and/or devices that output electrical power.For example, the electrical source 14 may be a power grid, an electricalgenerator, an alternator, an energy storage system (e.g., anotherbattery system), or the like.

Additionally, as depicted, the battery system 12 is electricallyconnected to the electrical load 16, which may enable the battery system12 to supply electrical power to the electrical load 16. In someembodiments, the electrical load 16 may include one or more machines,components, and/or devices that use the electrical power to performoperations and/or capture the electrical power as electrical energy. Forexample, the electrical load 16 may include a computer, an enginecontrol unit, a display, a light bulb, an electrical motor, an energystorage system (e.g., another battery system), a heating, ventilating,and air conditioning (HVAC) system, or the like.

In the depicted embodiment, the battery system 12 includes one or morebattery modules 24 and a battery control system 26. In some embodiments,the battery control system 26 may control operation of the batterysystem 12. For example, the battery control system 26 may determineoperational parameters of battery modules 24, coordinate operation ofmultiple battery modules 24, communicate control commands instructingthe battery system 12 to perform control actions, and/or communicatewith the supervisory control system 18.

To facilitate controlling operation, the battery control system 26 mayinclude a processor 28 and memory 30. In some embodiments, the memory 30may include a tangible, non-transitory, computer readable medium thatstores data, such as instructions executable by the processor 28,results (e.g., operational parameters) determined by the processor 28,and/or information (e.g., operational parameters) to beanalyzed/processed by the processor 28. Thus, in such embodiments, thememory 30 may include random access memory (RAM), read only memory(ROM), rewritable non-volatile memory (e.g., flash memory), hard drives,optical discs, and the like. Additionally, the processor 28 may includeone or more general purpose processing units, processing circuitry,and/or logic circuitry. For example, the processor 28 may include one ormore microprocessors, one or more application-specific integratedcircuits (ASICs), and/or one or more field programmable logic arrays(FPGAs).

Additionally, to facilitate storing electrical energy and supplyingelectrical power, the battery system 12 may include one or more batterymodules 24. In some embodiments, storage capacity of the battery system12 may be based at least in part on number of battery modules 24.Additionally, in some embodiments, operational compatibility of thebattery system 12 with the electrical system 10 may be based at least inpart on configuration of the battery modules 24, for example, in seriesand/or in parallel to operate in a target voltage domain. According, insome embodiments, implementation (e.g., number and/or configuration) ofthe battery modules 24 and, thus, the battery system 12 may vary basedat least in part on configuration and/or target application of theelectrical system 10.

However, as described above, electrical systems 10 may be utilized in awide-range of applications. As such, implementation of different batterysystem 12 may vary from one another. For example, in some embodiments,the electrical system 10 may be included in a stationary power system,an industrial system, a manufacturing system, an automation system, orthe like, such as a factory or plant. Additionally, in some embodiments,the electrical system 10 may be included in a computing system, such asa computer, or an automotive system, such as an automotive vehicle(e.g., airplane, boat, truck, or car).

To provide an example of a possible application, an automotive vehicle32 utilizing a first battery system 12A is shown in FIG. 2. Discussionwith regard to the automotive vehicle 32 is merely intended to be helpillustrate the techniques of the present disclosure and not to limitscope of the techniques. In some embodiments, the automotive vehicle 32may be an xEV, which utilizes the battery system 12 to provide and/orsupplement vehicular motive force, for example, used to accelerateand/or decelerate the automotive vehicle 32. In other embodiments, theautomotive vehicle 32 may be a traditional automotive vehicle 32 thatproduces vehicular motive force, for example, using an internalcombustion engine to accelerate and/or frictional brakes to decelerate.

A more detailed view of the first battery system 12A and the electricalsystem 10 in the automotive vehicle 32 is shown in FIG. 3. As describedabove, the battery system 12 includes the battery control system 26 andone or more battery modules 24. Additionally, as described above, anelectrical system 10 may include an electrical source 14, an electricalload 16, and a supervisory control system 18 in addition the batterysystem 12. For example, in the depicted automotive vehicle 32, theelectrical load 16 may include a vehicle console 38 and a heating,ventilating, and air conditioning (HVAC) system 37. In some embodiments,the electrical load 16 may additional or alternatively include amechanical energy source 40 (e.g., an electric motor) operating in amotor mode.

Additionally, in the depicted automotive vehicle 32, the electricalsource 14 includes an alternator 42, which may convert mechanical energygenerated by the mechanical energy source 40 (e.g., an internalcombustion engine and/or rotating wheels) into electrical energy. Insome embodiments, the electrical source 14 may additionally oralternatively include the mechanical energy source 40 (e.g., an electricmotor) operating in a generator mode.

As depicted, the automotive vehicle 32 also includes a vehicle controlsystem 43. In some embodiments, the vehicle control system 43 maygenerally control operation of the automotive vehicle 32, which includesthe electrical system 10. Thus, in the depicted automotive vehicle 32,the supervisory control system 18 may be included in a vehicle controlsystem 43. However, the vehicle control system 43 may additionallycontrol operation of other components other that the electrical system10, such as an internal combustion engine propulsion system.

As described above, the number and/or configuration of battery modules24 in different battery systems 12 may vary based at least in part ontarget application. For example, in the depicted automotive vehicle 32,the battery system 12 includes two battery modules 24—namely a firstbattery module 24A and a second battery module 24B. In some embodiments,the first battery module 24A may include one or more battery cells 36connected in series and/or in parallel with terminals of the firstbattery module 24A. Similarly, in some embodiments, the second batterymodule 24B may include one or more battery cells 36 connected in seriesand/or in parallel with terminals of the second battery modules 24B.

In some embodiments, a battery system 12 may include multiple batterymodules 24 to facilitate operational compatibility with multiple voltagedomains. For example, in the depicted embodiment, the first batterymodule 24A may operate (e.g., receive and/or supply) using electricalpower in a first (e.g., high or 48 volt) voltage domain. On the otherhand, the second battery module 24B may operate using electrical powerin a second (e.g., low or 12 volt) voltage domain.

Additionally or alternatively, in some embodiments, a battery system 12may include multiple battery modules 24 to improve implementationflexibility and/or implementation ease. For example, when the firstbattery module 24A and the second battery module 24B are connected inseries, a single battery module 24 may instead be used. However, such abattery module 24 may be large, heavy, and/or produce a higher voltageat its terminals, thereby limiting ease of moving the battery module 24.Additionally, such a battery module 24 may limit implementationflexibility, for example, in another battery system 12 with the firstbattery module 24A and the second battery module 24B instead connectedin parallel.

Comparatively, FIG. 4 shows a second battery system 12B utilized in adifferent application, such as a stationary power system. As depicted,the second battery system 12B include a number of battery modules 24 inaddition to the first battery module 24A and the second battery module24B. In particular, the depicted battery system 12 includes multiplebattery chains 44, which each includes multiple battery modules 24connected in series, connected in parallel between a positive bus 47 anda negative bus 49. For example, a first battery chain 44A includes Nnumber of battery modules 24 connected in series. In some embodiments,each battery module 24 may be intended to be electrically identical and,thus, each battery chain 44 may include the same number of batterymodules 24.

Due at least in part to the different number of battery modules 24, thebattery control system 26 utilized in the first battery system 12A andthe battery control system 26 utilized in the second battery system 12Bmay be different. For example, instead of merely coordinating operationof the first battery module 24A and the second battery module 24B, thebattery control system 26 in the second battery system 12B maycoordinate operation of multiple battery chains 44. In other words,different battery control system 26 may perform different controlfunctions—particularly when used in different applications.

To help account for the different control functions, a battery controlsystem 26 may be implemented based at least in part on a battery controlsystem architecture. Generally, multiple different battery controlsystem architectures may be capable of implementing a battery controlsystem 26. However, the multiple different battery control systemarchitectures may have varying effects on implementation flexibilityand/or implementation associated cost.

For example, it may be possible to implement a battery system 12 using apurely centralized battery control system architecture specificallydesigned for the battery control system 26. Since specifically designedfor the battery system 12, the purely centralized battery control systemarchitecture may reduce amount of redundant infrastructure, therebyreducing implementation associated cost. However, the purely centralizedbattery control system architecture is generally unique to the batterycontrol system 26, thereby limiting implementation flexibility (e.g.,number of compatible battery system variations).

On the other extreme, it may be possible to implement a battery controlsystem 26 using a purely distributed battery control systemarchitecture, which provides a basic building block for each potentialcontrol function that may be implemented in a battery system 12. In thismanner, the building blocks in the purely distributed battery controlsystem architecture may be used to implement a wide variety of batterycontrol system 26, thereby improving implementation flexibility.However, the purely distributed battery control system architecture mayresult in increasing amount of redundant infrastructure. For example,since each building block may communicate with another building block,increasing number of building blocks may increase communicationinfrastructure (e.g., communication interfaces and/or busses) used toimplement a battery control system 26, thereby increasing implementationassociated cost.

Leveraging advantages of the two extremes, in some embodiments, a hybridbattery control system architecture may be used to implement batterycontrol system 26 with improved implementation flexibility and/orreduced implementation associated cost. In particular, a hybrid batterycontrol system architecture may provide basic building blocks that eachprovides different levels (e.g., abstractions or granularity) ofcontrol. For example, the basic building blocks may include a cellcontrol unit 46 that provides battery module level and/or battery celllevel control functions. Additionally, the basic building blocks mayinclude a system control unit 48 that provides battery system levelcontrol functions.

Furthermore, the basic building blocks may include a string control unit50 that provides battery string level control functions. As used herein,a battery string is intended to describe one or more battery modules 24connected in series. Thus, a battery chain 44 may include one or morebattery strings 52. In some embodiments, a battery chain 44 may bedivided into multiple battery strings 52 to facilitate maintainingcontrol granularity without significantly increasing control complexity.For example, in the depicted embodiment, a battery chain 44 is dividedinto three M number of battery modules 24—namely a first battery string52A, a second battery string 52B, and a third battery string 52C.

Moreover, a hybrid battery control system architecture may provideinfrastructure used in each of the building blocks. For example, ahybrid battery control system architecture may specify processinginfrastructure, power infrastructure, and/or communicationinfrastructure included in each of the cell control unit 46, the systemcontrol unit 48, and the string control unit 50. In some embodiments,the processing infrastructure may indicate one or more processor units,processing circuitry, and/or logic circuitry used in a building block.Additionally, the communication infrastructure may indicate one or morecommunication interfaces used in a building block.

Furthermore, the power infrastructure may indicate one or more isolationbarrier 56 used in and/or target operating voltage domain of a buildingblock. As described above, a battery system 12 may operate in multipledifferent voltage domains. For example, in the depicted embodiment, thebattery modules 24 may operate in a high voltage domain. Thus, thebattery modules 24 may act as a high voltage power source that supplieselectrical power to electrical components designed to operate usingelectrical power in the high voltage domain, which may include a portionof the battery control system 26. However, another portion of thebattery control system 26 may be designed to operate using electricalpower in a low voltage domain and, thus, receive electrical power from alow (e.g., external) voltage power source 54.

Due to different portions operating in different voltage domains, thebattery control system 26 may include one or more isolation barriers 56.In particular, an isolation barrier 56 may electrically isolateelectrical components operating in a first (e.g., high) voltage domainand electrical components operating in a second (e.g., low) voltagedomain. Additionally, in some embodiments, an isolation barrier 56 mayelectrically isolate the battery system 12 from a common ground (e.g.,system ground), such as a vehicle chassis or a device housing.

In this manner, a battery control system 26 may be implemented using thebuilding blocks specified in a hybrid battery control systemarchitecture, for example, based at least in part on target functions tobe provided by the battery control system 26 and functions provided byeach of the building blocks. However, in some instances, multipledifferent hybrid battery control system architectures may be expected toenable implementing a battery control system 26. Moreover, in someinstances, the multiple different hybrid battery control systemarchitectures may each have varying effects on implementationflexibility and/or implementation associated cost.

In other words, determining an appropriate hybrid battery control systemarchitecture may be a complex process. Thus, in some embodiments, adesign system may be used to facilitate determining a hybrid batterycontrol system architecture used to implement battery control system 26,for example, by selecting the hybrid battery control system architecturefrom multiple candidates based on various factors.

Design System for Hybrid Battery Control System Architecture

To help illustrate, one embodiment of a design system 58 that may beused to determine a hybrid battery control system architecture is shownin FIG. 5. In the depicted embodiment, the design system 58 iscommunicatively coupled to one or more battery systems 12, acommunication network 60, one or more input devices 62, and one or moreoutput devices 64. It should be appreciated that the depicted embodimentis merely intended to be illustrative of components that may becommunicatively coupled to the design system 58. For example, in otherembodiments, the design system 58 may be communicatively coupled to anycombination of the battery system 12, the communication network 60,input devices 62, and output devices 64.

In any case, the communication network 60, the input devices 62, and/orthe output devices 64 may facilitate communication to and/orcommunication from the design system 58. For example, the communicationnetwork 60 may enable the design system 58 to communicate with otherelectronic devices. Thus, in some embodiments, the communication network60 may be a personal area network (PAN), such as a Bluetooth network, alocal area network (LAN), such as an 802.11x Wi-Fi network, a wide areanetwork (WAN), such as a 4G or LTE cellular network, a controller areanetwork (CAN), and/or a local interconnect network (LIN).

Additionally, the input devices 62 may facilitate user interaction withthe design system 58, for example, by receiving user inputs. Thus, insome embodiments, the input devices 62 may include a button, a keyboard,a mouse, a trackpad, and/or the like. Furthermore, the output device 62may facilitate user interaction with the design system 58, for example,by indicating determined information. Thus, in some embodiments, theoutput device 64 may include an electronic display, a speaker, and/orthe like.

To facilitate determining the hybrid battery control systemarchitecture, the design system may include a design processor 68 anddesign memory 70. In some embodiments, the design memory 70 may includea tangible, non-transitory, computer readable medium that storesinstructions executable by the design processor 68. Thus, in suchembodiments, the design memory 70 may include random access memory(RAM), read only memory (ROM), rewritable non-volatile memory (e.g.,flash memory), hard drives, optical discs, and the like. Additionally,the design processor 68 may include one or more general purposeprocessing units, processing circuitry, and/or logic circuitry. Forexample, the design processor 68 may include one or moremicroprocessors, one or more application-specific integrated circuits(ASICs), and/or one or more field programmable logic arrays (FPGAs).

As described above, the design system 58 may determine the hybridbattery control system architecture by selecting from multiplecandidates based on various factors, such as implementation flexibilityand/or implementation associated cost. In some embodiments, the designsystem 58 may analyze the multiple candidates based at least in part onan objective function 72. In particular, the objective function 72 mayindicate a metric that takes into account expected ability of acandidate to achieve the various factors. Thus, in some embodiments, thedesign system 58 may store the objective function 72 in the designmemory 70, receive the objective function via the input devices 62,and/or receive the objective function via the communication network 60.Additionally, in some embodiments, the design system 58 may indicate thedetermined hybrid battery control system via the output devices 64and/or the communication network 60 to facilitate implementing a batterycontrol system 26 using the hybrid battery control system.

Furthermore, in some embodiments, the design system 58 may receive oneor more of the candidates via the communication network 60 and/or theinputs device 62. Additionally or alternatively, the design system 58may determine one or more of the candidate via analysis of one or morebattery systems 12 and/or battery control systems 26 the hybrid batterycontrol system architecture is intended to be compatible with. Forexample, in some embodiments, the design system 58 may determine acandidate based at least in part on target control levels that may beimplemented in the battery control systems 26, target functions to beprovided by the battery control system 26, and/or infrastructure used toimplement each target function.

To help illustrate, one embodiment of a process 74 for determining ahybrid battery control system architecture is described in FIG. 6.Generally, the process 74 includes determining target control levels ina battery control system (process block 76), determining targetfunctions of the battery control system (process block 78), determininginfrastructure to implement each of the target functions (process block80), and dividing the target functions between the control levels(process block 82). In some embodiments, the process 74 may beimplemented by executing instructions stored in a tangible,non-transitory, computer-readable medium, such as the design memory 70,using a processor, such as the design processor 68.

Accordingly, in some embodiments, the design system 58 may determinetarget control levels in battery control systems 26 intended to beimplementable using the hybrid battery control system architecture(process block 76) and target functions to be provided at each of thetarget control levels (process block 78). In some embodiments, thedesign system 58 may receive the target control levels and/or the targetfunctions from the communication network 60 and/or the input devices 62,for example, based on manual user input. Additionally or alternatively,to facilitate determining the target control level and/or the targetfunctions, the design system 58 may analyze battery systems 12 in whichthe battery control systems 26 are used. By analyzing a battery system12, the design system 58 may determine implementation (e.g., hierarchalorganization) of the battery system 12.

For example, by analyzing the second battery system 12B of FIG. 4, thedesign system 58 may determine number and/or target operating parametersof the battery cells 36, the battery modules 24, the battery strings 52,and/or the battery chains 44 in the second battery system 12B. Inparticular, the design system 58 may determine that the second batterysystem 12B is implemented with battery modules 24 each including aspecific number (e.g., four or sixteen) battery cells 36. Additionally,the design system 58 may determine that the second battery system 12B isimplemented with a specific number (e.g., three) battery strings 52 perbattery chain 44.

Based at least in part on the implementation of the battery system 12,the design system 58 may determine control levels that may be used in abattery control system 26 of the battery system 12. For example, withregard to the second battery system 12B of FIG. 4, the design system 58may determine that a battery control system 26 may provide a cellcontrol level, a module control level, a string control level, and/orsystem control level. Additionally, based at least in part on theimplementation of the battery system 12, the design system 58 maydetermine target functions to be provided at each of the control levels.

To help illustrate, one embodiment of a process 84 for determiningtarget functions at different control levels is described in FIG. 7.Generally, the process 84 includes determining target cell levelfunctions (process block 86), determining target module level function(process block 88), determining string level functions (process block90), and determining system level functions (process block 92). In someembodiments, the process 84 may be implemented by executing instructionsstored in a tangible, non-transitory, computer-readable medium, such asthe design memory 70, using a processor, such as the design processor68.

Accordingly, in some embodiments, the design system 58 may determinetarget cell level functions (process block 86). In particular, thedesign system 58 may determine control functions that a battery controlsystem 26 would potentially want to employ to control operation ofbattery cells 36 in a battery system 12. In some embodiments, thecontrol functions employed by a battery control system 26 may bedependent on implementation of the battery cells 36 in the batterysystem 12, such as number of battery cells 36 in the battery system 12,number of battery cells 36 per battery module 24, electrical connectionof battery cells 36 in the battery modules 24, target operating voltageof the battery cells 36, target operating current of the battery cells36, power rating of the battery cells 36, storage capacity of thebattery cells 36, and/or target operating temperature of the batterycells 36.

Thus, based at least in part on the battery cell implementation, thedesign system 58 may determine the target cell level functions. In someembodiments, the design system 58 may determine that the target celllevel functions include determining operational parameters (e.g.,voltage) of a battery cell 36, for example, to detect faults in thebattery cell 36. The design system 58 may also determine that the targetcell level functions include providing control commands, for example, todisconnect a battery cell 36 when a fault is detected in the batterycell 36, to control supply of electrical power to (e.g., charging) thebattery cell 36, and/or to control supply of electrical power (e.g.,discharging) from the battery cell 36.

Additionally, the design system 58 may determine target module levelfunctions (process block 88). In particular, the design system 58 maydetermine control functions that a battery control system 26 wouldpotentially want to employ to control operation of battery modules 24 ina battery system 12. In some embodiments, the control functions employedby a battery control system 26 may be dependent on implementation of thebattery modules 24 in the battery system 12, such as number of batterymodules 24 in the battery system 12, number of battery modules 24 perbattery string 52, number of battery modules 24 per battery chain 44,target operating voltage of the battery modules 24, power rating of thebattery modules 24, storage capacity of the battery modules 24, and/ortarget operating temperature of the battery modules 24.

Thus, based at least in part on the battery module implementation, thedesign system 58 may determine the target module level functions. Insome embodiments, the design system 58 may determine that the targetmodule level functions include determining operational parameters (e.g.,voltage) of a battery module 24, for example, to detect faults in thebattery module 24. Additionally, the design system 58 may determine thatthe target module level functions include coordinating operation ofmultiple battery cells 36 in the battery modules 24, for example, suchthat the multiple battery cells 36 operate at approximately the samevoltage and/or approximately the same current. Furthermore, the designsystem 58 may determine that the target module level functions includeproviding control commands, for example, to disconnect a battery module24 when a fault is detected in the battery module 24, to control supplyof electrical power to (e.g., charging) the battery module 24, and/or tocontrol supply of electrical power (e.g., discharging) from the batterymodule 24.

Furthermore, the design system 58 may determine target string levelfunctions (process block 90). In particular, the design system 58 maydetermine control functions that a battery control system 26 wouldpotentially want to employ to control operation of battery strings 52 ina battery system 12. In some embodiments, the control functions employedby a battery control system 26 may be dependent on implementation of thebattery strings 52 in the battery system 12, such as number of batterystrings 52 in the battery system 12, number of battery strings 52 perbattery chain 44, target operating voltage of the battery strings 52,and/or target operating current of the battery strings 52.

Thus, based at least in part on the battery string implementation, thedesign system 58 may determine the target string level functions. Insome embodiments, the design system 58 may determine that the targetstring level functions include determining operational parameters (e.g.,voltage) of a battery string 52, for example, to detect faults in thebattery string 52. Additionally, the design system 58 may determine thatthe target string level functions include coordinating operation ofbattery modules 24 in the battery string 52, for example, such that themultiple battery modules 24 operate at approximately the same voltageand/or approximately the same current. Furthermore, the design system 58may determine that the target string level functions include providingcontrol commands, for example, to disconnect a battery string 52 when afault is detected in the battery string 52, to control supply ofelectrical power to (e.g., charging) the battery string 52, and/or tocontrol supply of electrical power (e.g., discharging) from the batterystring 52.

The design system 58 may also determine target system level functions(process block 92). In particular, the design system 58 may determinecontrol functions that a battery control system 26 would potentiallywant to employ to control operation of a battery system 12. In someembodiments, the control functions employed by a battery control system26 may be dependent on implementation of the battery system 12, such astarget operating voltage of the battery system 12 and/or targetoperating current of the battery system 12.

Thus, based at least in part on the battery system implementation, thedesign system 58 may determine the target system level functions. Insome embodiments, the design system 58 may determine that the targetsystem level functions include determining operational parameters (e.g.,voltage) of a battery system 12, for example, to detect faults in thebattery system 12. Additionally, the design system 58 may determine thatthe target system level functions include coordinating operation ofmultiple battery strings 52 in the battery system, for example, suchthat the multiple battery strings 52 operate at approximately the samevoltage and/or approximately the same current. Furthermore, the designsystem 58 may determine that the target string level functions includeproviding control commands, for example, to disconnect a battery system12 when a fault is detected in the battery system 12, to control supplyof electrical power to (e.g., charging) the battery system 12, and/or tocontrol supply of electrical power (e.g., discharging) from the batterysystem 12.

In this manner, the design system 58 may determine target functions of abattery control system 26. As described above, in some embodiments, thetarget functions may be determined at multiple different control level,for example, to determine target cell level functions, target modulelevel functions, target string level functions, and/or target systemlevel functions. As should be appreciated, the target functions may bedetermined for any number of control levels. For example, in someembodiments, the target functions may include target chain levelfunctions. Moreover, in some embodiments, the target functions may bedetermined at a single control level—particularly in less complexbattery system 12, for example, with fewer number of battery modules 24.

Returning to the process 74 of FIG. 6, the design system 58 maydetermine infrastructure expected to be used in a battery system 12 toimplement each of the target functions (process block 80). In someembodiments, to facilitate implementing a target function, a batterycontrol system 26 may communicate data, process data, and/or utilizeelectrical power. Thus, in some embodiments, the design system 58 maydetermine communication infrastructure, processing infrastructure,and/or power infrastructure expected to be utilized to implement thetarget functions.

To help illustrate, one embodiment of a process 94 for determininginfrastructure expected to be utilized to implement target functions isdescribed in FIG. 8. Generally, the process 94 includes determiningprocessing infrastructure to implement a target function (process block96), determining communication infrastructure to implement the targetfunction (process block 98), and determining power infrastructure toimplement the target function (process block 100). In some embodiments,the process 94 may be implemented by executing instructions stored in atangible, non-transitory, computer-readable medium, such as the designmemory 70, using a processor, such as the design processor 68.

Accordingly, in some embodiments, the design system 58 may determineprocessing infrastructure expected to be used to implement a targetfunction (process block 96). In some embodiments, the battery controlsystem 26 may utilize different types of processing infrastructure, suchas analog-to-digital converters (ADCs), logic circuitry, processorunits, and/or processing circuitry, to process and/or analyze data usedfor controlling operation. Thus, in some embodiments, the design system58 may determine number and/or type of processing infrastructureexpected to be used to implement the target function.

Additionally, the design system 58 may determine communicationinfrastructure expected to be used to implement the target function(process block 98). In some embodiments, the battery control system 26may utilize different types of communication infrastructure, such asserial communication interfaces, parallel communication interfaces,serial communication busses and/or parallel communication busses, tocommunicate data externally and/or internally between differentcomponents. Thus, in some embodiments, the design system 58 maydetermine number and/or type of communication infrastructure expected tobe used to implement the target function.

Furthermore, the design system 58 may determine power infrastructureexpected to be used to implement the target function (process block100). In some embodiments, the battery control system 26 may consumeelectrical power to facilitate processing and/or communicating data.Thus, in some embodiments, the design system 58 may determine targetoperating voltage (e.g., voltage domain) of components in the batterycontrol system 26 (process block 102) and power source expected to beused to supply electrical power at the target operating voltage (processblock 106).

As described above, in some embodiments, different portions of thebattery control system 26 may operate in different voltage domains and,thus, may include an isolation barrier 56 therebetween. Accordingly, insome embodiments, the design system 58 may determine whether portions ofthe battery control system 26 used to implement the target functionoperate in different voltage domains and determine whether an isolationbarrier 56 is expected to be used to implement the target function basedat least in part on whether portion of the battery control system 26expected to be used to implement the target function operate indifferent voltage domains.

In this manner, the design system 58 may determine infrastructure of abattery control system 26 expected to be used to implement one or moretarget functions. As described above, in some embodiments, a targetfunction may be implemented using processing infrastructure,communication infrastructure, and/or power infrastructure. As should beappreciated, in other embodiments, other types of infrastructure mayadditionally or alternatively be used to implement a target functionand, thus, determined by the design system. For example, in someembodiments, the infrastructure to implement a target function mayinclude other physical infrastructure, such as spacing infrastructure,packaging infrastructure, and/or switching (e.g., relay, contactor,and/or circuit breaker) infrastructure.

Returning to the process 74 of FIG. 6, the design system 58 maydetermine a hybrid battery control system architecture by assigningtarget functions and associated infrastructure to building blocks(process block 82). In particular, the design system 58 may determinewhich of the target functions to assign to building blocks. As describedabove, a target function may be implemented used infrastructure in thebuilding blocks, thereby affecting implementation associated cost, suchas building block size, packing of a building block (e.g., within abattery module), component count, operational power consumption, and/orcomponent cost. Additionally, providing a target function may increasenumber of different battery control system 26 capable of beingimplemented, thereby affecting implementation flexibility.

Thus, to determine which target functions to provide, the design system58 may evaluate effect providing each target function is expected tohave of implementation flexibility and/or implementation associatedcost. In some embodiments, to facilitate balancing the expected effects,the design system 58 may utilize the objective function 72. For example,based on the objective function 72, the design system 58 may exclude atarget function expected to be utilized in fewer battery control systems26 since the increase in implementation associated cost—particular inbattery control systems 26 that do not utilize the target function—mayoutweigh the improved implementation flexibility resulting fromproviding the target function. On the other hand, based on the objectivefunction 72, the design system may assign a target function expected tobe utilized in more battery control system 26 since the improvedimplementation flexibility may outweigh the increase in implementationassociated cost resulting from providing the target function.

In some instances, multiple target functions may at least partiallyoverlap. For example, a function to determine current flowing through abattery string 52 may also indicate the current flowing through abattery modules 24 in the battery string 52. Additionally, a function toinstruct a relay to disconnect a battery string 52 may also disconnect abattery module in the battery string 52. Furthermore, a function todetermine voltage across a battery module 24 may at least provide anindication of voltage across the battery cells 36 in the battery module24.

Thus, in some embodiments, the design system 58 may determine targetfunctions to be assigned that at least partially overlap. In thismanner, to facilitate reducing implementation associated cost, thedesign system 58 may determine the hybrid battery control systemarchitecture such that some target functions along with associatedinfrastructure are centralized to fewer (e.g., one) building blocks. Inparticular, centralizing some target functions may facilitate reducingamount of redundant infrastructure used to implement a battery controlsystem 26, thereby reducing implementation associated cost.

Additionally, the design system 58 may determine the hybrid batterycontrol system architecture such that some target functions along withassociated infrastructure are distributed to multiple building blocks.In some instances, target functions provided by each building block mayaffect implementation flexibility. For example, when a string controlunit 50 and a cell control unit 46 are both capable of providing atarget function, a battery system 26 may implement the target functionusing a string control unit 50, a cell control unit 46, or both a stringcontrol unit 50 and a cell control unit 46. Thus, distributing sometarget functions may facilitate increasing number of compatible batterycontrol system 26 (e.g., with varying target control levels), therebyimproving implementation flexibility.

Accordingly, to facilitate determining whether to centralize ordistribute target functions, the design system 58 may determine theeffect centralizing and the effect distributing the target is expectedto have on implementation flexibility and/or implementation associatedcost. In some embodiments, to facilitate balancing the expected effects,the design system 58 may utilize the objective function 72. For example,based on the objective function 72, the design system 58 centralizecomputationally intensive functions in string control units 50, therebyfacilitating reduced processing infrastructure in cell control units 46,reduced processing infrastructure in system control units 48, and/orreduced communication infrastructure implemented in a battery controlsystem 26. Additionally, based on the objective function 72, the designsystem 58 may centralize communication functions used to facilitatecommunication between electrical components operating in differentvoltage domains in string control units 50, thereby facilitating reducednumber of isolation barriers 56 cell control units 46 and/or systemcontrol units 48.

Furthermore, based on the objective function 72, the design system 58may centralize communication functions used to facilitate communicationwith external components in a system control unit 48, thereby facilitatereduced communication infrastructure in the cell control units 46 and/orstring control units 50. Moreover, based on the objective function 72,the design system 58 may centralize functions used to determine someoperational parameters. For example, centralizing a currentdetermination function in string control units 50 may obviatecommunication infrastructure, which may otherwise be used to communicatethe current flow from a cell control unit 46 to a string control unit50.

On the other hand, based on the objective function 72, the design system58 may distribute less computationally complex functions to differentcontrol levels to facilitate improving control granularity. For example,the design system 58 may distribute voltage determination functions tocell control units 46 and string control units 50, thereby enabling abattery control system 26 to determine at any combination of multipledifferent control levels. In this manner, the design system 58 maydetermine the hybrid battery control system architecture to enableimplementing battery control system 26 with different control levels.For example, the hybrid battery control system architecture may enableimplementing a battery control system 26 with only a system controllevel as well as a battery control system 26 with a module controllevel, a string control level, and a system control level.

Moreover, in some embodiments, providing multiple control levels mayfacilitate improving operation of the battery control system 26. In someembodiments, this may facilitate improving diagnostics, for example, byenabling the battery control system 26 to better locate the cause offault. For example, when a fault is detected in a battery string 52, bydetermining operational parameters at the module control level, thebattery control system 26 may identify a specific battery module 24 asthe cause of the fault, thereby enabling the specific battery module 24to be replaced instead of the entire battery string 52.

In this manner, utilizing the techniques described above, the designsystem 58 may determine a hybrid battery control system architecturethat improves implementation flexibility and/or reduces implementationassociated cost of battery control systems 26. In some embodiments,implementation flexibility and implementation associated cost may beinversely related. Thus, by utilizing the objective function 72, thedesign system 58 may strike a target balance between expected effect onimplementation flexibility and expected effect on implementationassociated cost. In fact, in some embodiments, the design system 58 mayadjust the objective function 72 to facilitate determining a hybridbattery control system architecture that strikes a different targetbalance between implementation associated cost and implementationflexibility. In other words, the design system 58 may be capable ofdetermining multiple different hybrid battery control systemarchitectures that result in different balances between implementationflexibility and implementation associated cost. To help illustrate, someexample hybrid battery control system architectures are described below.

Example Hybrid Battery Control System Architecture

One example of a hybrid battery control system architecture used toimplement the battery control system 26 in the second battery system 12Bis shown in FIG. 9. As depicted, the second battery system 12B includesthe low voltage power source 54 and battery modules 24 (e.g., a highvoltage power source), which each includes battery cells 36.Additionally, the second battery system 12B includes battery chains 44connected in parallel between the positive bus 47 and the negative bus49, which each includes battery modules 24 connected in series andorganized in battery strings 52.

Furthermore, the battery control system 26 is implemented using cellcontrol units 46, string control units 50, and a system control unit 48as provided by the hybrid battery control system architecture. Asdescribed above, the hybrid battery control system architecture mayindicate system level functions to be provided by the system controlunit 48. For example, the system level functions may includecentralizing communication between the battery control system 26 andexternal components, such as a supervisory control system 18.Additionally, the system level functions may include the system levelfunctions may include coordinating operation of battery strings 52 inthe battery system 12 and/or supplying electrical power to the stringcontrol units 50.

Thus, in some embodiments, the system control unit 48 may beelectrically coupled to the low voltage power source 54, therebyenabling the system control unit 48 to receive electrical power.Additionally, in some embodiments, the system control unit 48 may beelectrically coupled to the string control units 50, thereby enablingthe system control unit 48 to supply electrical power to the stringcontrol units 50. Furthermore, in some embodiments, the system controlunit 48 may be communicatively coupled to the string control units 50,thereby enabling the system control unit 48 to communicate instructions(e.g., control commands) to the string control units 50. To enableproviding the system level functions, as described above, the hybridbattery control system architecture may indicate infrastructure used inthe system control unit 48.

To help illustrate, one embodiment of a system control unit 48 (e.g., abuilding block) that may be specified by the hybrid battery controlsystem architecture is shown in FIG. 10. As depicted, the system controlunit 48 includes a parallel communication interface 110, a serialcommunication interface 112, a processing unit 114, memory 116, anexternal communication interface 118, and a system relay communicationinterface 120. It should be appreciated that the described componentsare merely intended to be illustrative. In other words, in actualimplementation, the system control unit 48 may include additionalcomponents and/or fewer components.

With regard to the depicted embodiment, the processing infrastructure ina system control unit 48 includes the processing unit 114, whichexecutes instructions stored in memory 116 to provide the system levelfunctions. Thus, in some embodiments, the processing unit 114 mayinclude one or more microprocessors and the memory 116 may include atangible, non-transitory, computer readable medium that storesinstructions executable by the processing unit 114. Thus, in suchembodiments, the memory 116 may include random access memory (RAM), readonly memory (ROM), rewritable non-volatile memory (e.g., flash memory),hard drives, optical discs, and the like.

As described above, the system control unit 48 may coordinate operationof the battery system 12. To facilitate coordinating operation, theprocessing unit 114 may process and/or analyze operational parametersrelated to operation of the battery system 12 (process block 122).Additionally, as described above, the system control unit 48 maycentralize external communication from the battery control system 26. Tofacilitate providing external communication, the processing unit 114 maygenerate external communication data and/or process received externalcommunication data (process block 124).

Thus, to facilitate providing the centralized external communicationfunction, the communication infrastructure includes the externalcommunication interface 118. In some embodiments, the externalcommunication interface 118 may communicatively couple to an externalcommunication network, thereby enabling the system control unit 48 totransmit and/or receive communication data with an external componentvia the external communication network. Additionally, to facilitateproviding the battery system coordination function, the communicationinfrastructure includes the parallel communication interface 110 and/orthe serial communication interface 112. In some embodiments, theparallel communication interface 110 may communicatively couple to aparallel communication network, such as a controller area network (CAN)and the serial communication interface 112 may communicatively couple toa serial communication network, such as a ripcord network. In thismanner, the parallel communication interface 110 and/or the serialcommunication interface 112 may enable the system control unit 48 totransmit instructions to and/or receive operational parameters from thestring control units 50.

Additionally, the communication infrastructure may include the systemrelay communication interface 120. In some embodiments, the system relaycommunication interface 120 may be communicatively coupled to a systemrelay, for example, which closes to connect the battery system 12 to anelectrical load 16 and opens to disconnect the battery system from theelectrical load 16. In this manner, the system relay communicationinterface 120 may enable the system control unit 48 to connect ordisconnect the battery system, for example, based at least in part onanalysis of received battery system operational parameters. In thismanner, the hybrid battery control system architecture may provide asystem control unit 48 building block along with associatedinfrastructure used to provide various system level functions.

Returning to the second battery system 12B shown in FIG. 9, as describedabove, the hybrid battery control system architecture may indicatestring level functions to be provided by each of the string controlunits 50. For example, the string level functions may includecoordinating operating of battery modules 24 in a corresponding batterystring 52. Additionally, the string level functions may includecentralizing communication from the corresponding battery string 52 tothe system control unit 48. Furthermore, the string level functions mayinclude providing more computationally complex functions at the stringcontrol level.

Thus, in some embodiments, a string control unit 50 may becommunicatively coupled to each cell control unit 46 of the batterymodules 24 in a corresponding battery string 52. For example, in thedepicted embodiment, a first string control unit 50A may becommunicatively coupled to the cell control units 46 corresponding tobattery modules 24 in the first battery string 52A, a second stringcontrol unit 50B may be communicatively coupled to the cell controlunits 46 corresponding to battery modules 24 in the second batterystring 52B, and a third string control unit 50L may be communicativelycoupled to the cell control units 46 corresponding to battery modules 24in the third battery string 52C. In this manner, the string controlunits 50 may determine string level operational parameters based atleast in part on cell level operational parameters and/or module leveloperational parameters received from the cell control units 46.

Additionally, in some embodiments, the string control units 50 may beelectrically coupled to the one or more of the cell control units 46and/or battery modules 24, thereby enabling the string control unit 50to receive high voltage electrical power. In this manner, a stringcontrol unit 50 may determine additional string level operationalparameters, such as string current and/or string voltage.

Furthermore, as described above, the string control units 50 may receivelow voltage electrical power from the system control unit 48. Tofacilitate reducing effect operation of the battery control system 26has on operation of battery system 12, the string control units 50 maygenerally operate using the low voltage electrical power received fromthe system control unit 48, for example, by boosting to high voltageelectrical power. However, since also receive high voltage electricalpower from the battery modules 24, the string control units 50 mayswitch to using the high voltage electrical power, for example, whensupply of the low voltage electrical power is disrupted. To enableproviding the string level functions, as described above, the hybridbattery control system architecture may indicate infrastructure used ineach string control unit 50.

To help illustrate, one embodiment of a string control unit 50 that maybe specified by the hybrid battery control system architecture is shownin FIG. 11. As depicted, the string control unit 50 includes a parallelcommunication interface 126, a serial communication interface 128,processing circuitry 130, a processing unit 132, memory 134, memory 134,a string relay communication interface 136, and an isolation barrier 56.It should be appreciated that the described components are merelyintended to be illustrative. In other words, in actual implementationthe string control unit 50 may include additional components and/orfewer components.

With regard to the depicted embodiment, the processing infrastructure ina string control unit 50 includes the processing circuitry 130 and theprocessing unit 132. In some embodiments, the processing circuitry 130and the processing unit 132 may provide at least partially overlappingstring level functions to improve reliability of the string control unit50—particularly since more computationally complex functions may becentralized in the string control unit 50. In addition to merely usingtwo different types of processing infrastructure, operationalreliability may be improved due at least in part on differentoperational principles of the processing circuitry 130 and theprocessing unit 132. In particular, the processing circuitry 130 mayoperate based on programmable circuit connections formed in theprocessing circuitry 130 and, thus, may include one or more fieldprogrammable logic arrays (FPGAs).

On the other hand, the processing unit 132 may operate by executinginstructions stored in memory 134. Thus, in some embodiments, theprocessing unit 132 may include one or more microprocessors and thememory 134 may include a tangible, non-transitory, computer readablemedium that stores instructions executable by the processing unit 132.Thus, in such embodiments, the memory 134 may include random accessmemory (RAM), read only memory (ROM), rewritable non-volatile memory(e.g., flash memory), hard drives, optical discs, and the like. In thismanner, likelihood of a disturbance affecting operation of both theprocessing circuitry 130 and the processing unit 132 simultaneously maybe reduced, thereby improving operational reliability of the stringcontrol unit 50.

As described above, the string control unit 50 may coordinate operationof battery modules 24 in a corresponding battery string 52. Tofacilitate coordinating operation, the processing unit 132 and/or theprocessing circuitry 130 may process and/or analyze operationalparameters related to operation of the battery modules 24 in the batterystring 52 (process block 138).

Thus, to facilitate providing the battery modules 24 coordinationfunction, the communication infrastructure includes the parallelcommunication interface 126 and/or the serial communication interface128. In some embodiments, the parallel communication interface 126 maycommunicatively couple to a parallel communication network, such as acontroller area network (CAN), and the serial communication interface128 may communicatively couple to a serial communication network, suchas a ripcord network. In this manner, the parallel communicationinterface 110 and/or the serial communication interface 112 may enablethe string control unit 50 to receive cell level and/or module leveloperational parameters from the cell control units 50 and/or transmitinstructions to the cell control units 50. Additionally, the parallelcommunication interface 110 and/or the serial communication interface112 may enable the string control unit 50 to receive instructions (e.g.,control commands) from the system control unit 48 and/or communicationstring level operational parameters to the system control unit 48 and/oranother string control unit 50.

Moreover, to enable communication with components operating in differentvoltage domains, the serial communication interface 112 may include alow voltage serial communication interface that communicatively couplesto a low voltage serial communication network and/or a high voltageserial communication interface that communicatively couples to a highvoltage serial communication network. In this manner, in someembodiments, the low voltage serial communication interface maycommunicatively couple a string control unit 50 to the system controlunit 48 and/or another string control unit 50 via the low voltage serialcommunication network. Additionally, in some embodiments, the highvoltage serial communication interface may communicatively couple astring control unit 50 to one or more cell control units 48 via the highvoltage serial communication network. In a similar manner, in someembodiments, the parallel communication interface 110 may include a lowvoltage parallel communication interface that communicatively couples tothe low voltage parallel communication network and/or a high voltageparallel communication interface that communicatively couples to a highvoltage parallel communication network.

Furthermore, since the string control unit 50 receives high voltageelectrical power from the battery modules 24 and low voltage electricalpower from the low voltage power source 54, the power infrastructureincludes the isolation barrier 56. As described above, the isolationbarrier 56 may facilitate electrically isolating electrical componentsoperating in the high voltage domain and electrical components operatingin the low voltage domain. In some embodiments, number of isolationbarriers 56 may substantially affect implementation associated costcompared to other components, such as communication interfaces. Thus,the hybrid battery control system architecture may centralizeimplementation of isolation barrier 56 on a per battery string 52 basis,thereby facilitating reduced implementation associated cost. In thismanner, the hybrid battery control system architecture may provide astring control unit 50 building block along with infrastructure used toprovide various string level functions.

With regard to the depicted embodiment, the communication infrastructureof the string control unit 50 also includes the string relaycommunication interface 136. In some embodiments, the string relaycommunication interface 136 may be communicatively coupled to a stringrelay, which may be controlled to selectively connect a battery string52 electrically to the battery system 12 and/or an electrical load. Forexample, the string relay communication interface 136 may enable thestring control unit 50 to communicate a control command instructing thestring relay to open to disconnect the battery string 52 electricallyfrom the battery system 12. Additionally, the string communicationinterface 136 may enable the string control unit 50 to communicate acontrol command instructing the string relay to close to connect thebattery string 52 electrically to the battery system 12.

As described above, in some embodiments, multiple battery strings 52 maybe connected in series, for example, as a battery chain 44 with eachbattery string 52 utilizing a corresponding string control unit 50. Insuch embodiments, operating a string relay may selectively connect ordisconnect multiple battery strings 52. Thus, in such embodiments, astring relay may be communicatively coupled to the string communicationinterface 136 of one (e.g., master) string control unit 50, therebyenabling the one string control unit 50 to communicate control commandsto the string relay. In this manner, the string communication interface136 of other (e.g., subordinate) string control units 50 may becommunicatively coupled to other electrical components, such as a fan.

Returning to the second battery system 12B shown in FIG. 9, as describedabove, the hybrid battery control system architecture may indicate celllevel functions and/or module level functions to be provided by each ofthe cell control units 46. Additionally, in some embodiments, a cellcontrol unit 46 may be physically coupled to a corresponding batterymodule 24. For example, a first cell control unit 46A may be physicallycoupled to the first battery module 24A. In fact, in some embodiments, acell control unit 46 may be disposed on or within a housing of acorresponding battery module 24. Additionally, in some embodiments, acell control unit 46 may be electrically coupled to terminals of acorresponding battery module 24, thereby enabling the cell control unit46 to receive electrical power used to perform the cell level functionsand/or module level functions.

To facilitate coupling with and/or receiving electrical power frombattery modules 24, the hybrid battery control system architecture mayassign the cell control units 46 less computationally complex cell levelfunctions and/or module level functions. As described above, in someembodiments, the cell level functions may include determiningoperational parameters related to operation of battery cells 36. Forexample, each cell control unit 46 may determine operational parametersof its corresponding battery module 24 and operational parameters ofbattery cells 36 in the battery module 24. In the depicted embodiment,the first cell control unit 46A may determine voltage of the firstbattery module 24A, voltage of a first (e.g., top) group of batterycells 36 in the first battery module 24A, voltage of a second (e.g.,bottom) group of battery cells 36 in the first battery module 24A,and/or temperature of the battery module 24.

To facilitate determining the operational parameters, a cell controlunit 46 may receive sensor data from one or more sensors 108 indicativeof the operational parameters. Thus, in some embodiments, the sensors108 may include one or more voltage sensors and/or one or moretemperature sensors. For example, in the depicted embodiment, the firstcell control unit 46A may receive sensor data from a first sensor 108Aindicative of voltage of the first group of battery cells 36, whichincludes a first battery cell 36A and a second battery cell 36B.Additionally, the first cell control units 46A may receive sensor datafrom a second sensor 108B indicative of voltage of the first batterymodule 24A and sensor data from the second sensor 108B indicative of thesecond group of battery cells 36, which includes a third battery cell36C and a fourth battery cell 36D.

Additionally, as described above, the module level functions may includecentralizing communication from the corresponding battery module 24 to astring control unit 50. Furthermore, the cell level functions mayinclude coordinating operation of battery cells 36 and/or battery cellgroups in a corresponding battery module 24 based on determinedoperational parameters. To enable providing the cells level functions,as described above, the hybrid battery control system architecture mayindicate infrastructure used in each cell control unit 46.

To help illustrate, one embodiment of a cell control unit 46 that may bespecified by the hybrid battery control system architecture is shown inFIG. 12. As depicted, the cell control unit 46 includes a first sensorcommunication interface 140, a second sensor communication interface142, a first analog-to-digital converter 144, a second analog-to-digitalconverter 146, logic circuitry 148, and a serial communication interface150. It should be appreciated that the described components are merelyintended to be illustrative. In other words, in actual implementationthe cell control unit 46 may include additional components and/or fewercomponents.

With regard to the depicted embodiment, the processing infrastructure inthe cell control unit 46 includes the first analog-to-digital converter144, the second analog-to-digital converter 146, and the logic circuitry148 to provide cell level functions and/or module level functions. Inparticular, the first analog-to-digital converter 144 and/or the secondanalog-to-digital converter 146 may convert data from an analogrepresentation to a digital representation, for example, to facilitatefurther processing by the logic circuitry 148 and/or a string controlunit 50.

As described above, a cell control unit 46 may provide lesscomputationally complex functions to facilitate reducing implementationassociated cost, reducing size, and/or reducing affect power consumptionof the cell control unit 46 is expected to have on operation of acorresponding battery module 24. Thus, in some embodiments, the logiccircuitry 148 may operate based on relatively fixed circuit connectionformed in the logic circuitry 148, for example, to process and/oranalyze operational parameters related to operation of a correspondingbattery module 24 and/or battery cells 36 in the battery module 24(process block 151).

Thus, in some embodiments, the logic circuitry 148 may include one ormore one or more application-specific integrated circuits (ASICs),operational amplifiers, and/or logic gates. For example, in someembodiments, the logic circuitry 148 may perform arithmetic operations,such as addition operations, division operations, multiplicationoperations, and/or division operations. Additionally, in someembodiments, the logic circuitry 148 may perform logic operations, suchas AND operations, OR operations, XOR operations, NOT operations, and/orNAND operations.

To facilitate providing the battery cell 36 coordination function, thecommunication infrastructure includes the first sensor communicationinterface 140 and/or the second sensor communication interface 142. Insome embodiments, the first sensor communication interface 140 maycommunicatively couple to the first sensor 108A, thereby enabling thecell control unit 46 to receive analog representations of sensor dataand the first analog-to-digital converter 144 to convert the analogrepresentation of the sensor data to a digital representation forfurther processing. Additionally the second sensor communicationinterface 142 may communicatively couple to the second sensor 108B,thereby enabling the cell control unit 46 to receive analogrepresentations of sensor data and the second analog-to-digitalconverter 146 to convert the analog representation of the sensor data toa digital representation for further processing.

Furthermore, to facilitate a string control unit 50 to provide themodule level coordination function, the communication infrastructure ofthe cell control unit 46 include the serial communication interface 150,thereby enabling the cell control unit 46 to communicate cell leveloperational parameters and/or module level operational parameters to astring control unit 50, for example, via the high voltage serialcommunication network. In this manner, the hybrid battery control systemarchitecture may provide a cell control unit 46 building block alongwith associated infrastructure used to provide various cell/module levelfunctions.

In some embodiments, the design system 58 may facilitate implementing abattery control system 26 using the hybrid battery control systemarchitecture. In some embodiments, the design system may analyze abattery system 12 and indicate building blocks from the hybrid batterycontrol system architecture to be used to implement a correspondingbattery control system 26. For example, returning to the second batterysystem 12B shown in FIG. 9, the design system 58 detect battery modules24 and indicate a cell control unit 46 to be electrically coupled toeach battery module 24. Additionally, the design system 58 may detectbattery strings 52 and indicate a string control unit 50 to becommunicatively and/or electrically coupled to cell control units 46corresponding to battery modules 24 in each battery string 52.Furthermore, the design system 58 may indicate a system control unit 48to be communicatively coupled to string control units 50 correspondingbattery strings 52 in the battery system 12B.

In some embodiments, based at least in part on the indication ofimplementation of building blocks in a battery control system 26, thedesign system 58 may relatively automatically implement the batterycontrol system 26. In other embodiments, the design system 58 maycommunicate the indication of the building blocks to a manufacturingsystem that implementations of the battery control system 26, forexample, via the communication network 60 and/or output devices 64.Furthermore, in some embodiments, the design system 58 may communicationthe indication of the building blocks to enable a user (e.g., operatoror manufacturer) to implement the battery control system 26, forexample, via the communication network 60 and/or output devices 64.

Additionally, as described above, the hybrid battery control systemarchitecture may enable expanding the battery control system 26 toprovide additional control level functions. For example, to providechain level functions, a chain control unit 153 may be communicativelycoupled to a string control unit 50 used with a battery string 52 in thecorresponding battery chain 44. As described above, using other hybridbattery control system architectures may provide result in varyingeffects on implementation flexibility and/or implementation associatedcost.

Example Hybrid Battery Control System Architecture with IntegratedString Control Unit

To help illustrate, the second battery system 12B including a batterycontrol system 26 implemented using another hybrid battery controlsystem architecture is shown in FIG. 14. As depicted, the second batterysystem 12B includes battery chains 44 connected in parallel between thepositive bus 47 and the negative bus 49, which each includes batterymodules 24 connected in series and organized in battery strings 52.Additionally, the battery control system 26 is implemented using cellcontrol units 46, integrated string control units 150, and a systemcontrol unit 48 as provided by the hybrid battery control systemarchitecture. In some embodiments, the cell control units 46 and/or thesystem control unit 48 provided by the currently described hybridbattery control system architecture may relatively the same as in thepreviously described hybrid battery control system architecture.

However, the currently described hybrid battery control systemarchitecture may specify integrated string control units 150 that varyat least partially in provided functions and/or infrastructure comparedto the string control units 50 provided by the previously describedhybrid battery control system architecture. In particular, since abattery string 52 generally includes at least one battery module 24, anintegrated string control unit 150 may integrate cell/module levelfunctions with string level functions. In this manner, redundantinfrastructure used to implement the battery control system 26 may bereduced, thereby facilitating reduced implementation associated cost.

In some embodiments, an integrated string control unit 150 may providestring level functions for a battery string 52 and cell/battery levelfunctions for one battery module 24 in the battery string 52. Forexample, in the depicted embodiment, a first integrated string controlunit 150A may provide string level functions for the first batterystring 52A and cell/battery level functions for one battery module 24 inthe first battery string 52A. Additionally, a second integrated stringcontrol unit 150B may provide string level functions for the secondbattery string 52B and cell/battery level functions for one batterymodule 24 in the second battery string 52B. Furthermore, a thirdintegrated string control unit 150L may provide string level functionsfor the third battery string 52C and cell/battery level functions forone battery module 24 in the second battery string 52B.

Thus, in some embodiments, an integrated string control unit 150 may bemay be physically coupled to the corresponding battery module 24 in thebattery string 52. For example, the first integrated string control unit150A may be physically coupled to the corresponding battery module 24 inthe first battery string 52A. In fact, in some embodiments, anintegrated string control unit may be disposed on and/or within ahousing of its corresponding battery module 24. In this manner, byproviding integrated string control units 150, the hybrid batterycontrol system architecture may facilitate reducing implementationassociated cost—particularly in less complex battery system 12 (e.g.,with fewer battery modules 24 and/or fewer control levels).

To help illustrate, one embodiment of an integrated string control unit150 that may be specified by the hybrid battery control systemarchitecture is shown in FIG. 14. As depicted, the integrated stringcontrol unit 150 includes an integrated cell control unit 152,processing circuitry 154, a processing unit 156, memory 158, anisolation barrier 56, a parallel communication interface 160, a serialcommunication interface 162, and a string relay communication interface164. It should be appreciated that the described components are merelyintended to be illustrative. In other words, in actual implementationthe integrated string control unit 150 may include additional componentsand/or fewer components.

With regard to the depicted embodiment, the functions provided by theintegrated cell control unit 152 may generally be the same as thefunctions provided by a cell control unit 46. As such, the processinginfrastructure of the integrated string control unit 150 includes theprocessing circuitry 154, the processing unit 156, and processinginfrastructure of the integrated cell control unit, such as the firstanalog-to-digital converter 144, the second analog-to-digital converter146, and/or the logic circuitry 148. In some embodiments, the processingcircuitry 154 and the processing unit 156 may operate to provide similarstring level functions as a string control unit 50. Additionally, insome embodiments, the string level functions provided by the processingcircuitry 154 and the processing unit 156 may at least partially overlapto facilitate improving operational reliability of the integrated stringcontrol unit 150.

For example, the processing circuitry 154 may operate based onprogrammable circuit connections formed in the processing circuitry and,thus, may include one or more field programmable logic arrays (FPGAs).Additionally, the processing unit 156 may operate by executinginstructions stored in memory 158. Thus, in some embodiments, theprocessing unit 156 may include one or more microprocessors and thememory 158 may include a tangible, non-transitory, computer readablemedium that stores instructions executable by the processing unit 156.Thus, in such embodiments, the memory 134 may include random accessmemory (RAM), read only memory (ROM), rewritable non-volatile memory(e.g., flash memory), hard drives, optical discs, and the like.

Additionally, when a battery string 52 including multiple batterymodules 24, the integrated string control unit 150 may coordinateoperation of its corresponding battery module 24 and operation of theother battery modules 24 in the battery string 52. To facilitatecoordinating operation, the communication infrastructure includes theparallel communication interface 160 and/or the serial communicationinterface 162. In some embodiments, the parallel communication interface160 may communicatively couple to a parallel communication network, suchas a controller area network (CAN), and the serial communicationinterface 162 may communicatively couple to a serial communicationnetwork, such as a ripcord network. In this manner, the parallelcommunication interface 160 and/or the serial communication interface162 may enable the integrated string control unit 150 to receive celllevel and/or module level operational parameters from and/or transmitinstructions to the cell control units 46 of other battery modules 24 inits corresponding battery string 52.

Additionally, in some embodiments, the serial communication interface162 may enable the integrated string control unit 150 to receive stringlevel operational parameters and/or self-configuration information fromother integrated string control units 150, for example, whichcorresponding to other battery strings 52 in the same battery chain 44.Furthermore, in some embodiments, the parallel communication interface160 and/or the serial communication interface 162 may enable theintegrated string control unit 150 to transmit string level operationalparameters to and/or receive instructions (e.g., control commands) froma system control unit 48.

With regard to the depicted embodiment, the communication infrastructureof the integrated string control unit 150 also includes the string relaycommunication interface 164. In some embodiments, the string relaycommunication interface 164 may be communicatively coupled to a stringrelay, which may be controlled to selectively connect a battery string52 electrically to the battery system 12 and/or an electrical load. Forexample, the string relay communication interface 164 may enable theintegrated string control unit 150 to communicate a control commandinstructing the string relay to open to disconnect the battery string 52electrically from the battery system 12. Additionally, the stringcommunication interface 164 may enable the integrated string controlunit 150 to communicate a control command instructing the string relayto close to connect the battery string 52 electrically to the batterysystem 12.

As described above, in some embodiments, multiple battery strings 52 maybe connected in series, for example, as a battery chain 44 with eachbattery string 52 utilizing a corresponding integrated string controlunit 150. In such embodiments, operating a string relay may selectivelyconnect or disconnect multiple battery strings 52. Thus, in suchembodiments, a string relay may be communicatively coupled to the stringcommunication interface 164 of one (e.g., master) integrated stringcontrol unit 150, thereby enabling the one integrated string controlunit 150 to communicate control commands to the string relay. In thismanner, the string communication interface 164 of other (e.g.,subordinate) integrated string control units 150 may be communicativelycoupled to other electrical components, such as a fan.

In some instances, including the integrated cell control unit 152 in theintegrated string control unit 150 may facilitate reducing redundantinfrastructure. For example, the communication infrastructure used toprovide cell/module level functions may be shared with the communicationinfrastructure used to provide string level functions. Additionally, insome embodiments, the processing infrastructure used to providecell/module level function may be shared with processing infrastructureused to provide string level functions. For example, the processingcircuitry 154 and/or the processing unit 156 may provide processing usedto implement the cell/module level functions in addition to the stringlevel functions, which may obviate use of separate logic circuitry inthe integrated string cell control unit 152. In this manner, byproviding the integrated string control unit 150, the hybrid batterycontrol system architecture facilitate reducing implementationassociated cost of battery control systems 26.

Moreover, by specifying the integrated string control unit 150, thehybrid battery control system architecture may enable implementing abattery control system 26 with fewer components (e.g., building blocks).For example, the hybrid battery control system architecture may enableimplementing a battery control system 26 for a battery system 12including one battery module 24 using a single integrated string controlunit 150, thereby obviating use of cell control units 46 and/or a systemcontrol unit 48. In this manner, the hybrid battery control systemarchitecture may also facilitate improving implementation flexibility.

To facilitate determining string level operational parameters, theintegrated string control unit 150 may receive high voltage electricalpower from the battery modules 24 and low voltage electrical power, forexample, directly from the low voltage power source 54 and/or via asystem control unit 48. Thus, the power infrastructure of the integratedstring control unit 150 includes the isolation barrier 56, whichelectrically isolates electrical components operating in the highvoltage domain and electrical components operating in the low voltagedomain.

Although electrically isolated, the integrated string control unit 150may still be communicatively coupled to a system control unit 48 and/orother electrical components, such as a supervisory control system 18.Thus, to facilitate communication, the isolation barrier 56 may includean isolated communication interface 166. In some embodiments, theisolated communication interface 166 may include one or more digitalcommunication busses, optocouplers, photocouplers, and/or opticalisolators. In this manner, the processing circuitry 154 and/or theprocessing unit 156 may be communicatively coupled to the communicationinfrastructure of the integrated string control unit 150 via theisolated communication interface 166.

Moreover, in some embodiments, the processing circuitry 154 and/orprocessing unit 156 may operate in a high voltage domain. However, tofacilitate reducing affect power consumption of battery control system26 has on operation of the battery system 12, the processing circuitry154 and/or the processing unit 156 may receive electrical power suppliedby the low voltage power source 54. To facilitate using electrical powersupplied from the low voltage power source 54, the isolation barrier 56may include a transformer 168. In operation, the transformer 168 mayreceive low voltage electrical power and generate high voltageelectrical power, which may then be supplied to the processing circuitry154 and/or the processing unit 156, while maintaining electricalisolation. When supply of electrical power from the low voltage powersource 54 is disrupted, the integrated string control unit 150 mayswitch to supplying electrical power to the processing circuitry 154and/or the processing unit 156 from the battery modules 24.

Moreover, to enable communication with components operating in differentvoltage domains, the serial communication interface 162 may include alow voltage serial communication interface that communicatively couplesto a low voltage serial communication network and/or a high voltageserial communication interface that communicatively couples to a highvoltage serial communication network. In this manner, in someembodiments, the low voltage serial communication interface maycommunicatively couple an integrated string control unit 150 to thesystem control unit 48 and/or another integrate string control unit 150via the low voltage serial communication network. Additionally, in someembodiments, the high voltage serial communication interface maycommunicatively couple an integrated string control unit 150 to one ormore cell control units 48 via the high voltage serial communicationnetwork. In a similar manner, in some embodiments, the parallelcommunication interface 160 may include a low voltage parallelcommunication interface that communicatively couples to the low voltageparallel communication network and/or a high voltage parallelcommunication interface that communicatively couples to a high voltageparallel communication network. In this manner, the hybrid batterycontrol system architecture may provide an integrated string controlunit 150 along with associated infrastructure used to provide variouscell level functions, module level functions, and string levelfunctions.

One embodiment of a process 170 for implementing an integrated stringcontrol unit 150 is described in FIG. 15. Generally, the process 170includes electrically coupling a cell control unit to a first powersource (process block 172), communicatively coupling the cell controlunit to processing circuitry and/or a processing unit (process block174), electrically coupling the processing circuitry and/or theprocessing unit to a transformer (process block 176), electricallycoupling the transformer to a second power source (process block 178),and communicatively the processing circuitry and/or the processing unitto a communication interface via an isolated communication interface(process block 180). In some embodiments, the process 170 may beimplemented by executing instructions stored in a tangible,non-transitory, computer-readable medium, such as the design memory 70,using a processor, such as the design processor 68, for example, by amanufacturer and/or a designer of the integrated string control unit150.

Accordingly, in some embodiments, the design system 58 may indicate anintegrated cell control unit 152 to be electrically coupled to a firstpower source (process block 172). As described above, the integratedcell control unit 152 may be electrically coupled to a correspondingbattery module 24. In other words, in such embodiments, the first powersource may be the battery module 24 and, thus, a high voltage powersource. Additionally, in some embodiments, the integrated cell controlunit 152 may be electrically coupled to the battery module 24, forexample, via terminals of the battery module 24 and/or an internal busin the battery module 24.

Additionally, the design system 58 may indicate the integrated cellcontrol unit 152 to be communicatively coupled to processing circuitry154 and/or a processing unit 156 (process block 174). In someembodiments, the integrated cell control unit 152 may be communicativelycoupled to the processing circuitry 154 and/or the processing unit 156via one or more internal communication busses. In this manner,communication infrastructure (e.g., communication interfaces) used tocommunicatively couple the integrated cell control unit 152 to acommunication (e.g., CAN or ripcord) network may be obviated.

Furthermore, the design system 58 may indicate the processing circuitry154 and/or the processing unit 156 to be electrically coupled to thetransformer 168 (process block 176) and the transformer to beelectrically coupled to a second power source (process block 178). Asdescribed above, in some embodiments, the transformer 168 may receivelow voltage electrical power from the low voltage power source 54. Inother words, in such embodiments, the second power source be the lowvoltage power source 54. Thus, in some embodiments, the transformer 168may be electrically coupled to the low voltage power source 54 via oneor more electrical busses and/or via a system control unit 48.

Additionally, as described above, the transformer 168 may generate highvoltage electrical power supplied to the processing circuitry 154 and/orthe processing unit 156. Thus, in some embodiments, the transformer 168may be electrically coupled to the processing circuitry 154 and/or theprocessing unit 156 via one or more electrical busses. Furthermore, asdescribed above, the transformer 168 may be connected across theisolation barrier 56 between a first (e.g., high) voltage domain and asecond (e.g., low) voltage domain. Thus, in operation, the transformer168 may facilitate supplying electrical power used to operate theprocessing circuitry 154 and/or the processing unit 156 in the firstvoltage domain using received electrical power in the second voltagedomain.

The design system 58 may also indicate the processing circuitry 154and/or the processing unit 156 to be communicatively coupled to the theparallel communication interface 160 and/or the serial communicationinterface 162 via the isolated communication interface 166 (processblock 180). In some embodiments, the processing circuitry 154 and/or theprocessing unit 156 may be communicatively coupled to the isolatedcommunication interface 166 via one or more internal communicationbusses. Additionally, in some embodiments, the isolated communicationinterface 166 may be communicatively coupled to the parallelcommunication interface 160 and/or the serial communication interface162 via one or more internal communication busses.

As described above, in an integrated string control unit 150, theprocessing circuitry 154 and the processing unit 156 may be located onan opposite side of the isolation barrier 56 from the parallelcommunication interface 160 and the serial communication interface 162.Thus, the isolated communication interface 166 may be connected acrossthe isolation barrier 56 to facilitate data communication betweenelectrical components operating in different voltage domains. In thismanner, in some embodiments, the isolated communication interface 166may facilitate data communication between the processing unit 156 and aparallel communication network via the parallel communication interface160. Additionally, in some embodiments, the isolated communicationinterface 166 may facilitate data communication between the processingcircuitry 154 and a serial communication network via the serialcommunication interface 162.

As described above, the serial communication network may communicativelycouple multiple integrated string control units 150 and/or multiplestring control units 50, for example, in a daisy chain. In someembodiments, the serial communication network may facilitatecommunicating string level operational parameters between the multipleintegrated string control units 150 and/or multiple string control units50, for example, to indicate when a fault is detected in a correspondingbattery string 52. Additionally, in some embodiments, the serialcommunication network may facilitate self-configuring one or more of themultiple integrated string control units 150 and/or one or more stringcontrol units 50, for example, to determine order in the serialcommunication network.

String Control Unit Auto-Configuration and Fault Communication

To help illustrate, one embodiment of string control units 50 connectedin a serial communication network 182 is shown in FIG. 16. It should beappreciated that the following techniques are described with regard tostring control units 50 merely to provide an illustrate example. Inother words, the following techniques may also be applied to integratedstring control units 150.

With regard to the depicted embodiment, the serial communication network182 (e.g., ripcord network) communicatively couples multiple stringcontrol units 50—namely a first string control unit 50A, a second stringcontrol unit 50B, and a third (e.g., last) string control unit 50L. Insome embodiments, the string control units 50 communicatively coupledvia the serial communication network 182 may correspond to batterystrings 52 included in the same battery chain 44. Thus, it should beappreciated that three string control units 50 are depicted merely toprovide an illustrative example. In other embodiments, the serialcommunication network 182 may include two string control units 50 ormore than three string control units 50.

In any case, to form the serial communication network 182, the stringcontrol units 50 are communicatively coupled via serial communicationbusses 184 (e.g., ripcord busses). In some embodiments, the serialcommunication busses 184 may be unidirectional communication busses. Insuch embodiments, to form the serial communication network, the stringcontrol units 50 may be connected via the serial communication busses184 in a daisy chain configuration. For example, in the depictedembodiment, the first string control unit 50A is communicatively coupledto the second string control unit 50B via a first serial communicationbus 184A and so on down the daisy chain until the last string controlunit 50L. Additionally, the last string control unit 50L iscommunicatively coupled to the first string control unit 50A via afeedback serial communication bus 184F.

In this manner, the string control units 50 may communicate serialcommunication (e.g., ripcord) signals down (e.g., through) the serialcommunication network 182 (e.g., daisy chain) and back to the firststring control unit 50A. Thus, in some embodiments, the first stringcontrol unit 50A may be considered the master string control unit.Additionally, the second string control unit 50B through last stringcontrol unit 50L may be considered subordinate string control units.

In some embodiments, communicating serial communication signal in thismanner may enable a master string control unit to determine number ofsubordinate string control units connected to the serial communicationnetwork 182 and self-configure based at least in part on the number ofsubordinate string control units. Additionally, in some embodiments,communicating serial communication signals in this manner may enable asubordinate string control unit to determine its order in the serialcommunication network 182 and self-configure based at least in part onthe determined order. Furthermore, in some embodiments, communicatingserial communication signals in this manner may facilitate communicatingwhen a fault is expected to be present to other string control units 50,for example, to enable the master string control unit to instruct astring relay to open when the fault is expected to be present.

To help illustrate, one embodiment of a process 186 for operating stringcontrol units 50 connected in a serial communication network 182 (e.g.,daisy chain) is described in FIG. 17. Generally, the process 186includes generating a serial communication signal in a master stringcontrol unit (process block 188), communicating the serial communicationsignal to a next string control unit in a serial communication network(process block 190), determining whether subordinate string controlunits remain in the serial communication network (decision block 192),and feeding back the serial communication signal to the master stringcontrol unit when no subsequent string control units remain (processblock 194). In some embodiments, the process 186 may be implemented byoperating processing circuitry, such as processing circuitry 130 orprocessing circuitry 154, based on programmable circuit connections.Additionally, in some embodiments, the process 186 may be implemented byexecuting instructions stored in a tangible, non-transitory,computer-readable medium, such as memory 134 or memory 158, using aprocessor, such as the processing unit 132 or the processing unit 156.

Accordingly, in some embodiments, the first (e.g., master) stringcontrol unit 50A may generate a first serial communication signal(process block 188). In some embodiments, the serial communicationsignal may include a high state and a low state. Additionally, in someembodiments, the serial communication signal may be a voltage signal ora current signal.

Furthermore, in some embodiments, the serial communication signal may befrequency modulated to communicate information. For example, when afault is not detected, the frequency of the serial communication signalgenerated by the first string control unit 50A may be a master frequency(e.g., 100 Hz), which indicates that the first string control unit 50Ais the master string control unit in the serial communication network182. On the other hand, when a fault is detected, the frequency of theserial communication signal generated by the first string control unit50A may be a fault frequency (e.g., 500 Hz), which indicates that afault has been detected.

The first string control unit 50A may then communicate the first serialcommunication signal to the second (e.g., next subordinate) stringcontrol unit 50B (process block 190). In some embodiments, the firststring control unit 50A may communicate the first serial communicationsignal to the second string control unit 50B via the first serialcommunication bus 184A. After receiving the first serial communicationsignal, the second string control unit 50B may determine frequency ofthe first serial communication signal and operate accordingly.

To help illustrate, one embodiment of a process 196 for operating asubordinate string control unit is described in FIG. 18. Generally, theprocess 196 includes receiving a serial communication signal at a stringcontrol unit (process block 198), determining whether a fault isdetected in a current battery string (decision block 200), outputtingthe serial communication signal with a fault frequency when a fault isdetected in the current battery string (process block 202), anddetermining frequency of the received serial communication signal when afault is not detected in the current battery string (process block 204).Additionally, the process 196 includes determining whether the frequencyof the received serial communication signal is equal to the faultfrequency (decision block 206), determining whether a fault has beenconfirmed in a previous battery string when the frequency of thereceived serial communication signal is equal to the fault frequency(decision block 208), and determining order of the string control unitin a serial communication network when the frequency of the receivedserial communication signal is not equal to the fault frequency or whena fault has not been confirmed for the previous battery string (processblock 210). Furthermore, the process 196 includes determining an orderfrequency (process block 212) and outputting a serial communicationsignal with the order frequency (process block 214). In someembodiments, the process 196 may be implemented by operating processingcircuitry, such as processing circuitry 130 or processing circuitry 154,based on programmable circuit connections. Additionally, in someembodiments, the process 196 may be implemented by executinginstructions stored in a tangible, non-transitory, computer-readablemedium, such as memory 134 or memory 158, using a processor, such as theprocessing unit 132 or the processing unit 156.

Accordingly, in some embodiments, the second string control unit 50B mayreceive the first serial communication signal from the first stringcontrol unit 50A (process block 198). As described above, in someembodiments, the second string control unit 50B may receive the firstserial communication signal via the first serial communication bus 184A.

Additionally, the second string control unit 50B may determine whether afault has be detected in the second battery string 52B, the secondstring control unit 50B, and/or cell control units 46 communicativelycoupled to the second string control unit 50B (decision block 200). Insome embodiments, the second string control unit 50B may determinewhether a fault is expected to be present in the second battery string52B based at least in part on string level operational parameters.Additionally, in some embodiments, the second string control unit 50Bmay determine whether a fault is expected to be present in the a batterymodule 24 and/or a battery cell 36 in the second battery string 52Bbased at least in part on cell/module level operational parameters. Forexample, as will be described in more detail below, cell control units46 corresponding to battery modules 24 in the second battery string 52Bmay indicate whether a fault is expected to be present to the secondstring control unit 50B.

In any case, when the second string control unit 50B determines that afault is expected to be present, the second string control unit 50B mayoutput a second serial communication signal with a fault frequency(process block 202). In some embodiments, the fault frequency may becommonly known by the string control units 50 as indicating that a faulthas been detected. For example, in some embodiments, the fault frequencymay be 500 Hz. Thus, by outputting the second serial communicationsignal with the fault frequency, the second string control unit 50B mayindicate to the other string control units 50 communicatively coupled tothe serial communication network 182 that a fault has been detected.

On the other hand, when the second string control unit 50B does notdetermined that a fault is expected to be present, the second stringcontrol unit 50B may determine frequency of the first serialcommunication signal (process block 204). In some embodiments, thesecond string control unit 50B may determine frequency of the firstserial communication signal by determining duration between pulses. Forexample, the string control unit 50B may determine that the frequency is100 Hz when the first serial communication signal alternates between thehigh state and the low state every 10 ms. Additionally, the secondstring control unit 50B may determine that the frequency is 500 Hz whenthe first serial communication alternates between the high state and thelow state every 2 ms.

In this manner, the second string control unit 50B may determine whetherthe frequency of the first serial communication signal is equal to thefault frequency (decision block 206). Additionally, when the faultfrequency is detected, the second string control unit 50B may confirmwhether a fault has been detected in another battery string 52 (decisionblock 208). In other words, in some embodiments, the second stringcontrol unit 50B may not immediately determine that a fault has beendetected in the battery system 12 as soon as the fault frequency hasbeen received.

Instead, since a detected fault may result in ceasing operation (e.g.,disconnecting) of at least a portion of the battery system 12, thesecond string control units 50B may wait a short duration beforeconfirming that the frequency of the first serial communication signalis in fact indicating that a fault has been detected. For example, thesecond string control unit 50B may utilize a counter that incrementswhen successive pulses of the first serial communication signal are atthe fault frequency. In this manner, the second string control unit 50Bmay confirm that a fault has been detected in another battery string 52after the counter reaches a count threshold (e.g., five). Thus, afterthe fault has been confirmed, the second string control unit 50B mayoutput the second serial communication signal with the fault frequencyto the other string control units 50 communicatively coupled to theserial communication network 182 (process block 202).

On the other hand, when the received frequency is not equal to the faultfrequency and/or a fault has not been confirmed, the second stringcontrol unit 50B may determine order of the second string control unit50B in the serial communication network 182 based at least in part onthe frequency of the first serial communication signal (process block210). In some embodiments, the master frequency indicating that a stringcontrol unit 50 is the master string control unit in a serialcommunication network may be commonly known by the string control units50 communicatively coupled to the serial communication network 182.Accordingly, when frequency of the first serial communication signal isthe master frequency, the second string control unit 50B may determinethat the previous string control unit 50 is the master string controlunit. In this manner, the second string control unit 50B may determinethat its order is second in the serial communication network 182 and/orthat it is the first subordinate string control unit 50 in the serialcommunication network 182.

Additionally, the second string control unit 50B may determine an orderfrequency that indicates its order in the serial communication network182 (process block 212). In some embodiments, the second string controlunit 50B may determine the order frequency based at least in part on thefrequency of the first serial communication signal. For example, asubordinate string control unit may determine its order frequency bydividing (e.g., in half) the received frequency. To help illustrate,when the frequency of the first serial communication signal is 100 Hz,the order frequency determined by the second string control unit 50B maybe 50 Hz.

The second string control unit 50B may then output the second serialcommunication signal with the order frequency, for example, via a serialcommunication bus 184 (process block 214). In this manner, a stringcontrol unit 50 that receives the second serial communication signal maydetermine order of the second string control unit 50B and self-configureaccordingly.

In particular, returning to the process 186 of FIG. 17, the secondstring control unit 50B may output the second serial communicationsignal to a next subordinate string control unit in the serialcommunication network 182 when subsequent string control units remain(arrow 216). Thus, utilizing the process 196 described above, each ofthe subordinate string control units in the serial communication network182 may operate to self-configure and/or indicate a detected fault. Forexample, when the third (e.g., last) string control unit 50L receivesthe second serial communication signal, the third string control unit50L may determine frequency of the second serial communication signal.When the frequency is the fault frequency (e.g., 500 Hz), the thirdstring control unit 50L may confirm whether a fault has been detectedand self-adjust operation accordingly, for example, by outputting athird serial communication signal with the fault frequency.Additionally, when the frequency of the second serial communicationsignal is an order frequency (e.g., 50 Hz), the third string controlunit 50L may determine that the second string control unit 50B is thefirst subordinate string control unit and, thus, that its order is thirdin the serial communication network 182 and/or that it is the secondsubordinate string control unit in the serial communication network 182.

On the other hand, the second string control unit 50B may feedback thesecond serial communication signal to the first (e.g., master) stringcontrol unit 50A when no subsequent string control units remain (processblock 194). Based at least in part on the feedback serial communicationsignal, the first string control unit 50A may determine whether a faulthas been detected in any of the other battery string 52 in a mannersimilar to the subordinate string control units. For example, the firststring control unit 50A may determine frequency of the second serialcommunication signal. Additionally, when the frequency is the faultfrequency (e.g., 500 Hz), the first string control unit 50A may confirmwhether a fault has been detected and self-adjust operation accordingly,for example, by outputting the first serial communication signal withthe fault frequency and/or instructing a string relay to open.

Additionally, based at least in part on the feedback serialcommunication signal, the first string control unit 50A may determineconfiguration of the serial communication network 182, which may includenumber of string control units 50 connected to the serial communicationnetwork 182 and/or number of subordinate control units connected to theserial communication network 182. In some embodiments, the first stringcontrol unit 50A may determine the configuration of the serialcommunication network 182 by comparing frequency of the feedback serialcommunication signal and the master frequency.

As described above, in some embodiments, subordinate string controlunits may determine order frequency by dividing received frequency by afactor (e.g., 2). Thus, when subordinate string control units determineorder frequency by dividing received frequency in half, the first stringcontrol unit 50A may determine the configuration of the serialcommunication network 182 based at least in part on number of times themaster frequency is halved to reach the frequency of the feedback serialcommunication signal. For example, when master frequency is 100 Hz andfrequency of the feedback serial communication signal is 50 Hz, thefirst string control unit 50A may determine that a total of two stringcontrol units 50 are connected to the serial communication network 182and/or that one subordinate string control unit is connected to theserial communication network 182. In a similar manner, when masterfrequency is 100 Hz and frequency of the feedback serial communicationsignal is 25 Hz, the first string control unit 50A may determine that atotal of three string control units 50 are connected to the serialcommunication network 182 and/or that two subordinate string controlunit are connected to the serial communication network 182.

In this manner, the first (e.g., master) string control unit 50A mayadjust operation based at least in part on configuration of the serialcommunication network 182. For example, based at least in part on numberof subordinate string control units connected to the serialcommunication network 182, the first string control unit 50A maydetermine number of string control units 50 to which the first stringcontrol units 50A may communicate control commands. Additionally, theconfiguration of the serial communication network 182 may provide thefirst string control unit 50A insight into implementation of a batterysystem 12. For example, based at least in part on total number of stringcontrol units connected to the serial communication network 182, thefirst string control unit 50A may determine number of battery strings 52connected in a battery chain 44.

To help illustrate the techniques describe above, a plot 218 providing avisual representation of the serial communication signals output by thefirst string control unit 50A, the second string control unit 50B, andthe third (e.g., last) string control unit 50L is shown in FIG. 19. Inparticular, the plot 218 includes a first waveform 220 that provides avisual representation of the first serial communication signal output bythe first string control unit 50A between t0 and t4. Additionally, theplot 218 includes a second waveform 222 that provides a visualrepresentation of the second serial communication signal output by thesecond string control unit 50B between t0 and t4. Furthermore, the plot224 includes a third waveform 222 that provides a visual representationof a third serial communication signal output by the third stringcontrol unit 50L between t0 and t4.

With regarding to the depicted embodiment, a fault may not be presentbetween t0 and t1. Thus, as depicted, the first string control unit 50Aoutputs the first serial communication signal with a 100 Hz frequency(e.g., master frequency). Additionally, as depicted, the second stringcontrol unit 50B outputs the second serial communication signal with a50 Hz frequency (e.g., half of received frequency). Furthermore, asdepicted the third string control unit 50L outputs the third serialcommunication signal with a 25 Hz frequency (e.g., half of receivedfrequency).

However, as t1, the first string control unit 50A determines that afault related to the first battery string 52A is expected to be present.Thus, as depicted, the first string control unit 50A starts outputtingthe first serial communication signal with a 500 Hz frequency (e.g.,fault frequency) at t1. Additionally, as depicted, the second stringcontrol unit 50B starts outputting the second serial communicationsignal with a 500 Hz frequency at t2 after five (e.g., counterthreshold) pulses of the first serial communication signal at 500 Hz.Furthermore, as depicted the third string control unit 50L startsoutputting the third serial communication signal with a 500 Hz frequencyat t3 after five pulses of the second serial communication signal at 500Hz.

In this manner, string control units 50 communicatively coupled via aserial communication network 182 may self-configure and/or communicatedetected faults. As described above, in some embodiments, the stringcontrol units 50 may detect a fault based at least in part on indicationof the fault from a cell control unit 46. However, in some embodiments,processing capabilities of cell control units 46 may be limited.Nevertheless, the cell control units 46 may provide fault detectionfunctions utilizing the processing infrastructure specified in theabove-described hybrid battery control system architectures.

Cell Control Unit Fault Detection

To help illustrate, one embodiment of a battery module 24 and a cellcontrol unit 46 are shown in FIG. 20. As described above, a batterymodule 24 may include multiple battery cells 36. With regard to thedepicted embodiment, the battery cells 36 in the battery module 24 aredivided between a first cell group 226 and a second cell group 228. Insome embodiments, the battery cells 36 may be equally divided betweenthe first cell group 226 and the second cell group 228. For example,when the battery module 24 includes sixteen battery cells 36, thebattery cells 36 may be divided such that first cell group 226 and thesecond cell group 228 each include eight battery cells 36.

Additionally, based on the hybrid battery control system architecturesdescribed above, the cell control unit 46 includes the first sensorcommunication interface 140, the second sensor communication interface142, the first analog-to-digital converter 144, second analog-to-digitalconverter 146, and the logic circuitry 148. As described above, thefirst sensor communication interface 140 may be communicatively to thefirst sensor 108A, which determines operational parameters of the firstcell group 226. Additionally, the second sensor communication interface142 may be communicatively coupled to the second sensor 108B, whichdetermines operational parameters of the second cell group 228, and athird sensor, which determines operational parameters of the batterymodule 24 as a whole.

For example, in some embodiments, the first sensor communicationinterface 140 may receive an analog representation of voltage of thefirst cell group 226 from the first sensor 108A. To facilitatesubsequent processing, the first analog-to-digital converter 144 maygenerate a digital representation of the voltage of the first cell group226. Additionally, the second sensor communication interface 142 mayreceive an analog representation of voltage of the second cell group 228from the second sensor 108B and an analog representation of voltage ofthe battery module 24 from the third sensor 108C. To facilitatesubsequent processing, the second analog-to-digital converter maygenerate a digital representation of the voltage of the second cellgroup 228 and a digital representation of the voltage of the batterymodule 24.

To facilitate detecting a fault using the cell control unit 46, thelogic circuitry 148 may process and/or analyze the digitalrepresentations of the measured voltage generated by the firstanalog-to-digital converter 144 and the second analog-to-digitalconverter 146. In particular, the logic circuitry 148 may includecomparison circuitry 230, such as an operational amplifier, tofacilitate comparing voltages. Additionally, the logic circuitry 147 mayarithmetic circuitry 232, such a logic adder, to facilitate addingvoltages.

One embodiment of a process 234 for detecting faults using a cellcontrol unit 46 is described in FIG. 21. Generally, the process 234includes determining an indication of a first cell group voltage using afirst analog-to-digital converter (process block 236), determining anindication of a second cell group voltage using a secondanalog-to-digital converter (process block 238), determining a firstindication of a battery module voltage using the secondanalog-to-digital converter (process block 240), determining a secondindication of the battery module voltage based at least in part on theindication of the first cell group voltage and the indication of thesecond cell group voltage (process block 244), determining whetherdifference between the first indication of the battery module voltageand the second indication of the battery module voltage is greater thana different threshold (decision block 246), determining that a fault isexpected to be present when the difference is greater than the differentthreshold (process block 246), and determining that a fault is notexpected to be present when the different is not greater than thethreshold (process block 248). In some embodiments, the process 234 maybe implemented by operating the logic circuitry 148 based on circuitconnections formed in the logic circuitry 148, for example, duringmanufacture of the logic circuitry 148.

Accordingly, in some embodiments, the logic circuitry 148 may determinea digital representation of the voltage of the first cell group 226(process block 236). As described above, in some embodiments, thevoltage of the first cell group 226 may be measured by the first sensor108A and communicated to the first sensor communication interface 140.Additionally, as described above, the measured voltage of the first cellgroup 226 may be converted to the digital representation of the voltageand communicated to the logic circuitry 148.

Additionally, the logic circuitry 148 may determine a digitalrepresentation of the voltage of the second cell group 228 (processblock 238). As described above, in some embodiments, the voltage of thesecond cell group 228 may be measured by the second sensor 108B andcommunicated to the second sensor communication interface 142.Additionally, as described above, the measured voltage of the secondcell group 228 may be converted to the digital representation of thevoltage and communicated to the logic circuitry 148.

Furthermore, the logic circuitry 148 may determine a digitalrepresentation of the measured voltage of the battery module 24 as awhole (process block 240). As described above, in some embodiments, thevoltage of the battery module 24 may be measured by the third sensor108C and communicated to the second sensor communication interface 142.Additionally, as described above, the measured voltage of the batterymodule 24 be converted to the digital representation of the voltage andcommunicated to the logic circuitry 148.

Based at least in part on the digital representation of the first cellgroup voltage and the digital representation of the second cell groupvoltage, the logic circuitry 148 may determine a calculated voltage ofthe battery module 24 (process block 242). In particular, the logiccircuitry 148 may use the arithmetic circuitry 232 to determine thecalculated voltage by adding together the first cell group voltage andthe second cell group voltage.

Additionally, the logic circuitry 148 may determine difference whetherdifference between the measured voltage of the battery module 24 and thecalculated voltage of the battery module 24 is greater than a differencethreshold (process block 244). To determine the difference, the logiccircuitry 148 may use the arithmetic circuitry 232 to subtract themeasured voltage from the calculated voltage or vice versa.Additionally, the logic circuitry 148 may use the comparison circuitry230 to determine whether the difference is greater than the differencethreshold.

In some embodiments, the difference threshold may be predetermined andstored in the circuitry of the logic circuitry 148. In otherembodiments, the difference threshold may be supplied to the logiccircuitry from a string control unit 50, an integrated string controlunit 150, a system control unit 48, a supervisory control system 18,and/or another electrical component, for example, based at least in parton user input. Additionally, in some embodiments, the differencethreshold may be set to facilitate detecting faults in one or morespecific components of the cell control unit 46, such as the firstanalog-to-digital converter 144 and/or the second analog-to-digitalconverter 146. In fact, in some embodiments, various differencethresholds may be used to determine faults in different components ofthe cell control unit 46 and/or to detect different types of faults inthe battery module 24. Furthermore, in some embodiments, the differencethreshold may vary based at least in part of the measured battery modulevoltage and/or the calculated battery module voltage. For example, thedifferent threshold may be a percentage of the measured battery modulevoltage.

Thus, when the difference is greater than the difference threshold, thelogic circuitry 148 may determine that a fault is expected to be presentin the cell control unit 46 (process block 246). When a fault isexpected to be present, the cell control unit 46 may indicate as much toa string control unit 50, an integrated string control unit 150, asystem control unit 48, and/or a supervisory control system 18. In thismanner, the hybrid battery control system architectures may specify cellcontrol units 46 that provide fault detection functions even withlimited processing capabilities, thereby improving operationalreliability while reducing implementation associated cost.

Accordingly, the technical effects of the techniques provided by thepresent disclosure include improving implementation flexibility and/orreducing implementation associated cost for implementing battery controlsystems. In some embodiments, a hybrid battery control systemarchitecture may be determined to provide building blocks (e.g., a cellcontrol unit, a string control unit, and a system control unit), whichmay be used to implement various battery control systems. To determinethe hybrid battery control system architecture, some functions to beprovided by battery control systems may be centralized into fewerbuilding blocks, thereby reducing redundant infrastructure and, thus,implementation associated cost of the battery control systems. On theother hand, some functions may be distributed to more building blocks,thereby providing various possible control levels that may be used inbattery control systems and, thus, improving implementation flexibility.Moreover, the technical effects of the present disclosure may includeimproving operational reliability of battery control systems by enablingfault detection in cell control units even when the cell control unitsinclude limited processing capabilities.

The specific embodiments described above have been shown by way ofexample, and it should be understood that these embodiments may besusceptible to various modifications and alternative forms. It should befurther understood that the claims are not intended to be limited to theparticular forms disclosed, but rather to cover all modifications,equivalents, and alternatives falling within the spirit and scope ofthis disclosure.

1. A battery system comprising: a first battery string comprising afirst battery module and a second battery module connected in series;and a battery control system configured to control operation of thebattery system, wherein the battery control system comprises: a firstcell control unit electrically coupled to the first battery module,wherein the first cell control unit is configured to determine firstmodule level operational parameters related to operation of the firstbattery module; a second cell control unit electrically coupled to thesecond battery module, wherein the second cell control unit isconfigured to determine second module level operational parametersrelated to operation of the second battery module; a first stringcontrol unit communicatively coupled to the first cell control unit andthe second cell control unit, wherein the first string control unit isconfigured to: determine first string level operational parametersrelated to operation of the first battery string based at least in parton the first module level operational parameters and the second modulelevel operational parameters; and control operation of the first batterystring based at least in part on the first string level operationalparameters; and a system control unit communicatively coupled to thefirst string control unit, wherein the system control unit is configuredto: determine system level operational parameters related to operationof the battery system based at least in part on the first string leveloperational parameters; and control operation of the battery systembased at least in part on the system level operational parameters. 2.The battery system of claim 1, comprising a second battery string,wherein: the second battery string comprises a third battery module anda fourth battery module connected in series; and the battery controlsystem comprises: a third cell control unit electrically coupled to thethird battery module, wherein the third cell control unit is configuredto determine third module level operational parameters related tooperation of the third battery module; a fourth cell control unitelectrically coupled to the fourth battery module, wherein the fourthcell control unit is configured to determine fourth module leveloperational parameters related to operation of the fourth batterymodule; a second string control unit communicatively coupled to thethird cell control unit, the fourth cell control unit, and the systemcontrol unit, wherein: the second string control unit is configured todetermine second string level operational parameters related tooperation of the second battery string based at least in part on thethird module level operational parameters and the fourth module leveloperational parameters; and the system control unit is configured tocoordinate operation of the first battery string and the second batterystring based at least in part on the first string level operationalparameters and the second string level operational parameters.
 3. Thebattery system of claim 2, comprising: a positive bus and a negative busconfigured to electrically couple the battery system to an electricalload, an electrical source, or both; and a battery chain comprising thefirst battery string and the second battery string connected in seriesbetween the positive bus and the negative bus; wherein the batterycontrol system comprises a chain control unit physically coupled to thefirst string control unit, wherein the chain control unit is configuredto determine chain level operational parameters related to operation ofthe battery chain.
 4. The battery system of claim 2, wherein the systemcontrol unit, to adjust operation of the battery system, is configuredto: determine whether a fault is detected in the battery system based atleast in part on the first string level operational parameters, thesecond string level operational parameters, or both; and instruct asystem relay to electrically disconnect the battery system from anelectrical load when the fault has been detected.
 5. The battery systemof claim 1, wherein the first string control unit comprises: a firstportion configured to operate using electrical power in a first voltagedomain received from the first battery string; a second portionconfigured to operate using electrical power in a second voltage domainreceived from the system control unit, an external power source, orboth, wherein the second voltage domain is different from the firstvoltage domain; and an isolation barrier configured to electricallyisolate the first portion of the first string control unit from thesecond portion of the first string control unit.
 6. The battery systemof claim 5, wherein the isolation barrier comprises: an isolatedcommunication interface configured to facilitate data communicationbetween the first portion and the second portion of the first stringcontrol unit across the isolation barrier; and a transformer configuredto: receive electrical power in the second voltage domain from thesystem control unit, an external power source, or both; and generateelectrical power in the first voltage domain supplied to the firstportion of the first string control unit.
 7. The battery system of claim1, wherein: the first battery module comprises a first battery cellgroup and a second battery cell group, wherein the first battery cellgroup comprises a first plurality of battery cells and the secondbattery cell group comprises a second plurality of battery cells; thefirst cell control unit, to determine the first module level operationalparameters, is configured to: determine a first cell group voltage ofthe first battery cell group; determine a second cell group voltage ofthe second battery cell group; and determine a first battery modulevoltage of the first battery module; the second battery module comprisesa third battery cell group and a fourth battery cell group, wherein thethird battery cell group comprises a third plurality of battery cellsand the fourth battery cell group comprises a fourth plurality ofbattery cells; and the second cell control unit, to determine the secondmodule level operational parameters, is configured to: determine a thirdcell group voltage of the third battery cell group; determine a fourthcell group voltage of the fourth battery cell group; and determine asecond battery module voltage of the second battery module.
 8. Thebattery system of claim 7, wherein: the first string control unit, todetermine the first string level operational parameters, is configuredto: determine a string voltage of the first battery string based atleast in part on the first cell group voltage, the second cell groupvoltage, the first battery module voltage, the third cell group voltage,the fourth cell group voltage, the second battery module voltage, or anycombination thereof; and determine a string current of the first batterystring; and the first string control unit, to adjust operation of thefirst battery string, is configured to: determine whether a fault hasbeen detected in the first battery string; and instruct a string relayto electrically disconnect the first battery string from the batterysystem.
 9. The battery system of claim 1, wherein the first cell controlunit comprises: a first sensor communication interface configured toreceive a first analog representation of a first cell group voltage froma first voltage sensor; a first analog-to-digital convertercommunicatively coupled to the first sensor communication interface,wherein the first analog-to-digital converter is configured to generatea first digital representation of the first cell group voltage based atleast in part on the first analog representation; a second sensorcommunication interface configured to: receive a second analogrepresentation of a second cell group voltage from a second voltagesensor; receive a third analog representation of a battery modulevoltage from a third sensor; a second analog-to-digital convertercommunicatively coupled to the second sensor communication interface,wherein the second analog-to-digital converter is configured to:generate a second digital representation of the second cell groupvoltage based at least in part on the second analog representation;generate a third digital representation of the battery module voltagebased at least in part on the third analog representation; logiccircuitry communicatively coupled to the first analog-to-digitalconverter and the second analog-to-digital converter, wherein the logiccircuitry is configured to perform a logic operation, an arithmeticoperation, or both based at least in part on the first digitalrepresentation, the second digital representation, the third digitalrepresentation, or any combination thereof; and a serial communicationinterface configured to communicatively couple the first cell controlunit to the first string control unit via a serial communicationnetwork.
 10. The battery system of claim 1, wherein the first stringcontrol unit comprises: a parallel communication interface configured tocommunicatively couple the first string control unit to a second stringcontrol unit and the system control unit via a parallel communicationnetwork; a low voltage serial communication interface configured tocommunicatively couple the first string control unit to the secondstring control unit and the system control unit via a low voltage serialcommunication network; a high voltage serial communication interfaceconfigured to communicatively couple the first string control unit tothe first cell control unit and the second cell control unit via a highvoltage serial communication network; an isolation barrier comprising atransformer and an electrically isolated communication interface,wherein the isolation barrier is configured to electrically isolate ahigh voltage portion of the first string control unit from a low voltageportion of the first string control unit; processing circuitrycommunicatively coupled directly to the high voltage serialcommunication interface and communicatively coupled to the parallelcommunication interface, the low voltage serial communication interface,or both via the electrically isolated communication interface, whereinthe processing circuitry is configured to determine the first stringlevel operational parameters by processing received data based at leastin part on programmable circuit connections; and a processing unitcommunicatively coupled directly to the high voltage serialcommunication interface and communicatively coupled to the parallelcommunication interface, the low voltage serial communication interface,or both via the electrically isolated communication interface, whereinthe processing unit is configured to determine the first string leveloperational parameters by processing the received data received based atleast in on executable instructions stored in memory.
 11. The batterysystem of claim 1, wherein the system control unit comprises: a parallelcommunication interface configured to communicatively couple the systemcontrol unit to the first string control unit and a second stringcontrol unit via a parallel communication network; a serialcommunication interface configured to communicatively couple the systemcontrol unit to the first string control unit and the second stringcontrol unit via a serial communication network; an externalcommunication interface configured to communicatively couple the batterysystem to an external communication network; and a processing unitcommunicatively coupled to the parallel communication interface, theserial communication interface, and the external communicationinterface, wherein the processing unit determine the system leveloperational parameters based at least in part on executable instructionsstored in memory.
 12. The battery system of claim 1, wherein the firstbattery module comprises: a plurality of battery cells; and a housingthat houses the plurality of battery cells and the first cell controlunit, wherein the first cell control unit does not include amicroprocessor or an isolation barrier.
 13. A method for implementing abattery control system used to control operation of a battery system,comprising: implementing a cell control unit to be used to determinefirst operational parameters related to operation of a battery moduleby: communicatively coupling a first analog-to-digital converter to afirst sensor communication interface to enable the cell control unit toreceive a first analog representation of first sensor data from a firstsensor and generate a first digital representation of the first sensordata; communicatively coupling logic circuitry to the firstanalog-to-digital converter to enable the logic circuitry to perform alogic operation, an arithmetic operation, or both based at least in parton the first digital representation of the first sensor data; andcommunicatively coupling a first serial communication interface to thelogic circuitry to enable the cell control unit to communicate datawithin the battery control system via a first serial communicationnetwork; and implementing a string control unit to be used to controloperation of a battery string comprising the battery module by:communicatively coupling processing circuitry, a first processing unit,or both directly to a second serial communication interface to enablethe string control unit to communicate data with the cell control unitvia the first serial communication network; forming a first isolationbarrier comprising an electrically isolated communication interfacebetween a third serial communication interface and the second serialcommunication interface; and communicatively coupling the processingcircuitry, the first processing unit, or both to the third serialcommunication interface via the electrically isolated communicationinterface to enable the string control unit to communicate data via asecond serial communication network.
 14. The method of claim 13,comprising implementing a system control unit to be used to controloperation of the battery system by: communicatively coupling a secondprocessing unit to a fourth serial communication interface to enable thesystem control unit to communicate data with the string control unit viathe second serial communication network; communicatively coupling thesecond processing unit to a first parallel communication interface toenable the system control unit to communicate data within the batterycontrol system via a parallel communication network; and communicativelycoupling the second processing unit to an external communicationinterface to enable the battery control system to centralize externalcommunication; wherein implementing the string control unit comprisescommunicatively coupling the processing circuitry, the first processingunit, or both to a second parallel communication interface via theelectrically isolated communication interface to enable the stringcontrol unit to communicate data with the system control unit via theparallel communication network.
 15. The method of claim 14, wherein:implementing the string control unit comprises communicatively couplingthe processing circuitry, the first processing unit, or both to a stringrelay communication interface to enable the string control unit toinstruct a string relay to connect or disconnect the battery string fromthe battery system; and implementing the system control unit comprisescommunicatively coupling the second processing unit to a system relaycommunication interface to enable the system control unit to instruct asystem relay to connect or disconnect the battery system from anelectrical load.
 16. The method of claim 13, wherein implementing thecell control unit comprises: electrically coupling the cell control unitto a terminal of the battery module to enable the cell control unit toreceive high voltage electrical power from the battery module and todetermine the first operational parameters based at least in part on thehigh voltage electrical power; physically coupling the cell control unitto a housing of the battery module; and forming the logic circuitry toenable the logic circuitry to perform the logic operation, thearithmetic operation, or both based at least in part on circuitconnection in the logic circuitry.
 17. The method of claim 13, whereinimplementing the string control unit comprises: forming programmablecircuit connections in the processing circuitry to enable the processingcircuitry to determine second operational parameters related tooperation of the battery string, determine control commands, or bothbased at least in part on the programmable circuit connections; andstoring instructions executable by the first processing unit in memoryto enable the first processing unit to determine the second operationalparameters, determine the control commands, or both by executing theinstructions; wherein forming the first isolation barrier comprisesforming the first isolation barrier to electrically isolate theprocessing circuitry and the first processing unit from the third serialcommunication interface.
 18. The method of claim 13, whereinimplementing the cell control unit comprises: communicatively coupling asecond analog-to-digital converter to a second sensor communicationinterface to enable the cell control unit to: receive a second analogrepresentation of second sensor data from a second sensor; and generatea second digital representation of the second sensor data; andcommunicatively coupling the logic circuitry to the secondanalog-to-digital converter to enable the logic circuitry to perform alogic operation, an arithmetic operation, or both based at least in parton the second digital representation of the second sensor data.
 19. Themethod of claim 13, wherein implementing the cell control unit comprisesimplementing the cell control unit without a microprocessor and withouta second isolation barrier.
 20. A tangible, non-transitory,computer-readable medium that stores instructions executable by one ormore processors of a design system to implement a battery controlsystem, wherein the instructions comprise instructions to: indicate,using the one or more processors, a first cell control unit to beelectrically coupled to a first battery module in a battery system toenable the first cell control unit to receive high voltage electricalpower from the first battery module and determine first operationalparameters related to operation of the first battery module; indicate,using the one or more processors, a first string control unit to becommunicatively coupled to the first cell control unit via a firstserial communication network to enable the first string control unit tocontrol operation of a first battery string comprising the first batterymodule based at least in part on the first operational parameters;indicate, using the one or more processors, a system control unit to be:communicatively coupled to the first string control unit via a secondserial communication network and a parallel communication network toenable the system control unit to coordinate operation of the firstbattery string with a second battery string in the battery system; andelectrically coupled to an external power source to enable the systemcontrol unit to receive low voltage electrical power from the externalpower source.
 21. The computer-readable medium of claim 20, comprisinginstructions to: indicate, using the one or more processors, the firststring control unit to be electrically coupled to the first batterymodule to enable the first string control unit to receive the highvoltage electrical power; and indicate, using the one or moreprocessors, the first string control unit to be electrically coupled tothe external power source to enable the first string control unit toreceive the low voltage electrical power; wherein the first stringcontrol unit comprises an isolation barrier to electrically isolate afirst portion of the first string control unit operating using the highvoltage electrical power from a second portion of the first stringcontrol unit operating using the low voltage electrical power.
 22. Thecomputer-readable medium of claim 20, comprising instructions toindicate, using the one or more processors, the system control unit tobe communicatively coupled to an external communication network toenable the battery control system to centralize communication with theexternal communication network through the system control unit.